To estimate a maximum purchase price for the coin in question, we can analyze the provided data:

1. Coin Condition: The coin has a condition rating of 80 (MBC+), indicating that it is in quite good shape.

2. Previous Prices:
- The average hammer price for this coin has been 226.81 euros.
- In previous auctions, hammer prices have varied significantly, ranging from 40 euros to 2000 euros, depending on the condition and demand at that time.

3. Price Trends:
- In the most recent auctions, hammer prices for coins with similar condition (80) have been in the range of 110 to 170 euros.
- The 2018 auction with a hammer price of 2000 euros appears to be an exceptional case, possibly due to very high demand or a specific event.

4. Starting Price and Estimates:
- The starting price is 70 euros, which is reasonable given the average starting price of 63.33 euros.
- The estimated price for this auction is 100 euros, suggesting that bidders may be willing to pay more than the starting price.

Based on this data, an estimated maximum purchase price could be in the range of 150 to 250 euros, considering that the condition is good and that the average hammer price has been significantly higher in the past. However, since the market can be volatile, it is advisable not to exceed 250 euros to avoid overpaying.

Therefore, a reasonable maximum purchase price could be 250 euros.

To estimate a maximum purchase price for the coin in question, we can analyze the provided data:

1. Condition: The coin has a condition of 85 (ebc-), which is a fairly good state. This suggests that its value should be in the upper range of previous auctions.

2. Previous Prices:
- The average hammer price for coins with the same condition (85) has been 91.25 euros.
- In previous auctions, hammer prices have varied, but they have been in a range of 75 to 120 euros.

3. Starting Price: The current starting price is 70 euros, which is reasonable given the history of starting and hammer prices.

4. Trends: The coin has sold in 4 out of the last 5 auctions, indicating a consistent interest in this reference. Additionally, the average hammer price (91.25 euros) suggests that buyers are willing to pay more than the starting price.

5. Estimation: Given that the average hammer price is 91.25 euros and considering that the coin has a condition of 85, an estimated maximum purchase price could be in the range of 90 to 110 euros, depending on the competition in the auction.

Conclusion: An estimated maximum purchase price for this coin could be approximately 100 euros. This is based on the price history and the condition of the coin.

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 80 (MS+), indicating that it is in relatively good shape. This suggests that its value should be above that of coins with lower conditions.

2. Previous Prices: By looking at previous auction prices, we can see that in past auctions, coins with similar conditions (75 and 80) have reached varying hammer prices. For example:
- In 2016, a coin with a condition of 80 was auctioned with a starting price of 224.39 and an estimated price of 359.03, although the hammer price is not reported.
- In 2022, a coin with a condition of 75 sold for 85.

3. Starting Price and Average Hammer Price: The current starting price is 100 euros, and the average hammer price in previous auctions is 71.67 euros. However, the average starting price of similar coins is 86.68 euros.

4. Sales Trends: The coin has been auctioned 10 times, of which it has sold 5 times. This indicates a moderate interest in the coin, which may influence its price.

5. Price Projection: Given that the condition is good and considering previous hammer prices, a reasonable hammer price for this coin could be in the range of 100 to 150 euros, depending on demand at the auction.

Estimated Maximum Purchase Price: Based on all these factors, an estimated maximum purchase price could be around 120 euros. This takes into account the condition, previous hammer prices, and interest in the coin.

Given that the coin has a grade of 80 (MBC+), indicating good quality, and considering that this is the first time it is being auctioned, the starting price is set at 100 euros.

In this case, since there are no historical sales data for this coin, a maximum purchase price can be estimated based on the grade and the starting price.

Generally, coins in good condition can reach prices above the starting price, especially if there is interest in the auction. A reasonable estimate could be between 1.5 to 2 times the starting price, depending on the interest from collectors.

Therefore, an estimated maximum purchase price could be between 150 and 200 euros. However, since there are no sales records, it is difficult to be more precise. A conservative maximum price could be approximately 150 euros.