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 70 (VF-). This indicates that it is in an acceptable state, but not of high quality.

2. Auction History:
- The average hammer price for coins of similar condition (around 70) has been approximately 15 to 20 euros in recent auctions.
- In the past, coins with a condition of 70 have reached hammer prices of up to 45 euros (as seen in the auction on 2020-10-21).

3. Starting Price and Average Starting Price:
- The current starting price is 12 euros, which is relatively low compared to the average hammer price of 32.94 euros.
- The average starting price of 17.98 euros also suggests that there is potential for an increase in the hammer price.

4. Recent Trends:
- In the most recent auctions, the hammer price has ranged between 15 and 30 euros for coins of similar condition.

Based on these factors, an estimated maximum purchase price for this coin could be between 25 and 35 euros. This is based on the historical hammer prices for coins of similar condition and the potential for an increase in the hammer price in the current auction.

Therefore, a reasonable maximum purchase price could be 30 euros.

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

1. Condition: The coin has a condition of 70 (MS-), which indicates that it is in quite good shape. This generally translates to a higher price compared to coins with lower conditions.

2. Auction history:
- The average hammer price for coins of similar condition (70) has been approximately 19.56 euros.
- In previous auctions, hammer prices for coins with a condition of 70 have ranged between 10 and 30 euros, with a most recent hammer price of 15 euros.

3. Starting price and previous prices:
- The current starting price is 12 euros, which is slightly lower than the average starting price of 13.82 euros.
- The estimated price for this auction is 20 euros, suggesting that there are expectations for the coin to sell at a higher price.

4. Sales trends: Of the 27 times it has been auctioned, it has sold 19 times, indicating good demand and consistent interest in this coin.

Taking all these factors into account, an estimated maximum purchase price could be around 25-30 euros, as this range aligns with previous hammer prices and the condition of the coin. However, it is important to consider that the final price may vary depending on competition in the auction and the interest of other bidders.

To estimate a maximum purchase price for the coin in question, we can analyze the provided data, especially considering the current condition of the coin (70, MBC-) and previous auction prices.

1. Condition: The coin has a condition of 70 (MBC-), indicating that it is in relatively good shape, although not of the highest quality (FDC).

2. Previous auction prices:
- In previous auctions, the coin has reached hammer prices that varied significantly. For example:
- In 2020, with a condition of 90, it sold for 220 euros.
- With a condition of 80, it sold for 30 euros.
- With a condition of 70, it sold for 18 euros.
- The average hammer price for coins in similar condition (70) has been approximately 18 euros.

3. Average starting and hammer price:
- The average starting price is 21.5 euros, and the average hammer price is 36.64 euros. This suggests that, in general, coins of this reference tend to sell for above their starting price.

4. Auction trends:
- The coin has been auctioned 13 times and has sold every time, indicating consistent demand.

Based on these factors, an estimated maximum purchase price for the coin in its current state (70, MBC-) could be in the range of 25 to 40 euros. This is based on the average hammer price of coins in similar condition and historical price behavior.

Therefore, a reasonable estimated maximum purchase price could be 35 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 rating of 30 (BC+), indicating that it is not in very good shape. This will negatively affect its value compared to coins in better condition.

2. Auction History:
- The average hammer price for similar coins in the past is 122.88 euros.
- However, the hammer prices for coins with similar conditions (30) are lower. For example, at the 2021 auction, a coin with a condition of 30 was sold for 14 euros.

3. Starting and Hammer Prices:
- The current starting price is 12 euros, which is relatively low.
- In previous auctions, starting prices have varied, but the highest hammer price for similar conditions has been 45 euros.

4. Sales Trends: The coin has been auctioned 10 times, of which it has sold 8 times, indicating good demand, although the hammer price can vary significantly.

5. Estimation Based on Previous Data: Given that the condition is low and considering the price history, a reasonable hammer price for this coin could be in the range of 15 to 30 euros, based on the lowest hammer price for similar conditions.

Conclusion: Taking all these factors into account, an estimated maximum purchase price for this coin could be approximately 30 euros. This would allow for competitive bidding in the auction without exceeding a reasonable limit given the coin's condition.