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

1. Coin Condition: The coin has a condition rating of 85 (ebc-), which indicates that it is in quite good shape. This generally translates to a higher price compared to coins with lower conditions.

2. Previous Auction Prices: By observing the hammer prices of coins with similar conditions (around 85-90), we can see that the hammer prices have varied. For example, in previous auctions, coins with a condition of 90 have reached hammer prices of up to 270 euros, while others with a condition of 80 have had lower hammer prices, around 15-70 euros.

3. Average Hammer Price: The average hammer price for this particular coin is 100.2 euros, which gives us a good reference point.

4. Starting Price and Estimates: The current starting price is 25 euros, and the average starting price in the past has been 61.42 euros. This suggests that interest in the coin may be higher, especially if the condition is good.

5. Auction Trends: Given that it has been auctioned 65 times and sold 58 times, this indicates a consistent interest in the coin, which may influence the price.

Taking all these factors into account, an estimated maximum purchase price for this coin could be in the range of 150 to 200 euros. This is based on the condition, previous hammer prices, and general interest in the coin. However, it is important to remember that the final price may vary depending on competition in the auction and other market factors at the time of sale.