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

1. Coin Condition: The coin has a condition rating of 80 (MS+), indicating that it is in quite good shape. This generally translates to a higher price compared to coins with lower conditions.

2. Previous Prices: By looking at the auction prices of coins with similar conditions (around 80), we can see that the hammer prices have varied. For example, in previous auctions, coins with a condition of 80 to 85 have reached hammer prices ranging from 50 to 110 euros.

3. Average Hammer Price: The average hammer price for this coin is 75.57 euros, which provides a good reference.

4. Recent Trends: In the most recent auctions, hammer prices for coins of similar condition have shown an increase, suggesting that interest in these coins may be growing.

5. Starting Price and Estimates: The starting price is 25 euros, and the average starting price is 53.19 euros. This indicates that there is a considerable margin between the starting price and the expected hammer price.

Taking all these factors into account, an estimated maximum purchase price for this coin could be between 100 and 120 euros, considering that the condition is good and there is growing interest in coins of this type. However, it is important to remember that the final price may vary depending on competition in the auction and other market factors.