To estimate a maximum purchase price for the coin with a grade of 30 (BC+), we can analyze historical data and price trends.

1. Data from previous auctions:
- The coin has been auctioned 101 times, of which it has sold 92 times.
- The average hammer price is 153.86 euros, but this value includes coins in better conditions.
- In previous auctions, hammer prices for coins in similar conditions (BC+) have varied, but they generally fall within a lower range.

2. Hammer prices for similar grades:
- In past auctions, hammer prices for coins with a grade of 30 (BC+) have been lower. For example, in a recent auction, a coin with a grade of 30 sold for 45 euros.
- Hammer prices for coins in grades of 70 and 80 have been significantly higher, indicating that the grade drastically affects the price.

3. Estimation based on starting price and average hammer price:
- The current starting price is 12 euros, suggesting that the seller expects moderate interest.
- Given that the average hammer price for coins in similar conditions has been approximately 20-45 euros, we can estimate that the maximum purchase price for this coin could be in the range of 30 to 50 euros.

Conclusion: Based on the grade of 30 (BC+) and historical data, an estimated maximum purchase price for this coin could be 45 euros.

To estimate a maximum purchase price for the coin in question, we will consider several factors:

1. Current Condition: The coin has a condition of 30 (BC+). This indicates that it is not in the best condition, which will affect its value.

2. Auction History:
- The average hammer price for similar coins has been 245.58 euros.
- In the past, coins with similar conditions (around 30) have been auctioned, and the hammer prices have varied. For example, in 2018, a coin with a condition of 30 was sold for 11 euros, while another with a condition of 80 was sold for 40 euros.

3. Price Trends:
- The current starting price is 12 euros, which is relatively low compared to the average hammer price.
- The coin has been auctioned 82 times, of which 78 have sold, indicating good demand.

4. Recent Hammer Prices:
- In recent auctions, hammer prices for coins with similar conditions have ranged between 10 and 65 euros.

Based on these factors, an estimated maximum purchase price for this coin could be between 30 and 50 euros, considering that the condition is not high and that the price history shows significant variations. This would allow for a competitive offer without exceeding the current market value.

To estimate a maximum purchase price for the coin in question, we can consider several factors:

1. Current Condition: The coin has a condition of 30 (BC+). This indicates that it is not in the best condition, which generally negatively affects its value.

2. Historical Prices: By looking at previous auction prices for coins with similar conditions, we can see that prices vary considerably. For example, in past auctions, coins with conditions ranging from 25 to 30 have had hammer prices ranging from 9 to 40 euros.

3. Average Hammer Price: The average hammer price for this coin is 114.55 euros, but this includes coins in better conditions. Given that the condition of this coin is lower, it is unlikely to reach that price.

4. Starting Price and Average Starting Price: The starting price is 12 euros, and the average starting price is 59.77 euros. This suggests that the market has moderate expectations for this coin.

5. Recent Trends: In the most recent auctions, hammer prices for coins with similar conditions have been lower, suggesting that interest may be declining.

Based on these factors, an estimated maximum purchase price for this coin could be between 25 and 35 euros. This reflects a balance between the current condition and historical prices, taking into account that market interest may influence the final price.

To estimate a maximum purchase price for the coin in question, we will consider several factors:

1. Current Condition: The coin has a grade of 25 (BC), indicating that it is not in very good condition. This generally reduces its value compared to coins in better condition.

2. Auction History:
- The average hammer price for coins of the same reference has been 107.29 euros.
- However, the hammer prices for coins with similar grades (25) have been significantly lower. For example, in previous auctions, the hammer prices for coins with grades of 25 and 30 have ranged from 15 to 30 euros.

3. Starting Price and Average Starting Price:
- The current starting price is 12 euros, and the average starting price is 54.55 euros. This suggests that the market has higher expectations, but the condition of the coin limits its appeal.

4. Recent Trends: In the most recent auctions, the hammer prices for coins with similar grades have been in the range of 19 to 30 euros.

Based on these factors, an estimated maximum purchase price for this coin, considering its condition and price history, could be between 25 and 30 euros. This reflects a balance between the state of the coin and previous hammer prices for coins in similar conditions.

To estimate a maximum purchase price for the coin in question, we can consider several factors:

1. Current Condition: The coin has a condition of 70 (VF-), which indicates that it is in relatively good shape, but not among the best qualities.

2. Historical Prices: By looking at previous auction prices for coins with a similar condition (70), we can see that the hammer price has varied. For example, in past auctions, coins with a condition of 70 have reached hammer prices of up to 80 euros.

3. Average Hammer Price: The average hammer price for this coin is 165.94 euros, but this includes coins of different conditions. Given that the condition of the coin in question is 70, it is likely that its hammer price will be below this average.

4. Recent Trends: In the most recent auctions, hammer prices for coins with a condition of 70 have been in the range of 25 to 40 euros, suggesting that interest and demand may be fluctuating.

5. Starting Price: The starting price is 15 euros, indicating that the auctioneer expects moderate interest.

Taking all these factors into account, an estimated maximum purchase price for this coin could be in the range of 40 to 60 euros. This is based on the current condition, previous hammer prices, and market trends.

To estimate a maximum purchase price for the coin in question, we will consider several factors:

1. Current Condition: The coin has a condition rating of 90 (EF), indicating that it is in quite good shape. This generally translates to a higher price compared to coins in lower conditions.

2. Sales History: By looking at previous auction prices for coins with similar conditions (around 90-95), we can see that auction prices have varied, but there are examples of auctions reaching up to 70 euros for coins in similar conditions.

3. Average Auction Price: The average auction price for this coin is 27.36 euros, providing a solid basis for estimating a maximum price.

4. Recent Trends: In the most recent auctions, the hammer prices have shown a range that can be higher, especially for coins in superior condition.

5. Starting Price: The starting price is 15 euros, suggesting that interest in the coin may be moderate, but given the sales history, it is likely that the final price will be significantly higher.

Based on these factors, an estimated maximum purchase price for the coin could be between 40 and 60 euros, considering that the condition is good and there is a history of auction prices supporting this estimate. However, to be more conservative, a maximum purchase price of 50 euros could be a good reference.

To estimate a maximum purchase price for the coin in question, we can consider several factors based on the provided data:

1. Current Condition: The coin has a condition of 30 (BC+). This indicates that it is not in the best condition, which will affect its value.

2. Previous Auction Prices: By looking at previous auction prices for coins with similar conditions, we can see that:
- In 2019, a coin with a condition of 30 was auctioned for 11 euros.
- In 2020, a coin with a condition of 25 was auctioned for 17 euros.
- In 2020, another coin with a condition of 30 was auctioned for 17 euros.

3. Average Auction Price: The average auction price for this coin is 86.5 euros, but this includes coins in better conditions. Given that the condition of the coin in question is quite low, it is unlikely to reach that price.

4. Starting Price and Average Starting Price: The starting price is 15 euros, and the average starting price is 42.43 euros. This suggests that interest in the coin may be moderate.

5. Sales Trends: The coin has been auctioned 83 times, of which 79 have been sold. This indicates a good level of interest in the coin, although the auction price can vary significantly depending on the condition.

### Estimation of Maximum Purchase Price
Given that the condition is 30 (BC+), and considering the previous auction prices for coins with similar conditions, a reasonable maximum purchase price could be in the range of 15 to 25 euros.

However, since the average auction price for coins in similar conditions has been around 17 euros, an estimated maximum purchase price could be 20 euros. This allows for some margin for competition in the auction, but also reflects the condition of the coin.

To estimate a maximum purchase price for the coin in question, we can consider several factors:

1. Coin Condition: The coin has a condition of 70 (MS-), which indicates that it is in an acceptable state, but not of the highest quality.

2. Historical Auction Data:
- The average hammer price for similar coins is 101.08 euros.
- In previous auctions, coins with a similar condition (70) have had hammer prices that vary, but there are examples where they have sold for between 25 and 120 euros.

3. Starting Price and Estimates:
- The current starting price is 15 euros, which is quite low compared to the average hammer price.
- The average starting price for similar coins is 69.06 euros.

4. Sales Trends:
- Out of the 165 times this coin has been auctioned, it has sold 143 times, indicating a good sales rate.

Based on these factors, an estimated maximum purchase price could be in the range of 80 to 120 euros, considering that the average hammer price is 101.08 euros and that the coin's condition is acceptable.

Therefore, a reasonable maximum purchase price could be 100 euros.

To estimate a maximum purchase price for the coin in question, we will consider several factors:

1. Coin Condition: The coin has a condition of 70 (MS-), indicating that it is in acceptable condition but not of high quality. This will affect the maximum price that can be offered.

2. Auction History: By observing previous hammer prices for coins with a similar condition (70), we can see that hammer prices have varied. For example:
- In previous auctions, coins with a condition of 70 have reached hammer prices ranging from 14 to 45 euros.
- The average hammer price for coins of similar condition seems to be around 30-40 euros.

3. Starting Price and Previous Hammer Prices: The current starting price is 15 euros, and the average hammer price in the past has been 49.04 euros. However, given that the condition is 70, it is likely that the hammer price will not reach the highest average.

4. Recent Trends: In the most recent auctions, hammer prices for coins of similar condition have been in the range of 25 to 35 euros.

Based on these factors, an estimated maximum purchase price for this coin could be between 30 and 40 euros, considering that the condition and price history suggest that this range should not be exceeded to ensure a reasonable purchase.

Therefore, a reasonable maximum purchase price could be 35 euros.