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. Auction History: By looking at previous hammer prices for coins with similar conditions, we can see that hammer prices have varied. For example, in recent auctions, coins with condition ratings of 80 have reached hammer prices of up to 110 euros.

3. Average Hammer Price: The average hammer price for this coin is 75.57 euros, providing a good reference for the expected value.

4. Auction Trends: The coin has been auctioned 205 times, with an 85% sell-through rate (174 times sold). This suggests that there is consistent interest in this coin, which may increase its value.

5. Starting Prices and Estimates: The starting price is 25 euros, and the average starting price is 53.19 euros. This indicates that the market is willing to pay more than the starting price on many occasions.

Based on these factors, an estimated maximum purchase price for this coin could be between 100 and 120 euros, considering that the condition is good and there is a history of hammer prices that supports this estimate.