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

1. Coin Condition: The coin has a condition of 80 (MS+), 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 previous auction prices of coins with a similar condition (80 or close), we can see that the hammer price has varied. For example, in past auctions, coins with a condition of 80 have reached hammer prices of up to 80-90 euros.

3. Average Hammer Price: The average hammer price for this coin is 128.03 euros, suggesting that, in general, coins of this reference tend to sell for higher prices.

4. Recent Trends: In the most recent auctions, hammer prices have shown a trend of stabilizing in a range of 40 to 90 euros for coins of similar condition.

5. Starting Price: The starting price is 25 euros, which may attract more bidders, but the final price will depend on the competition in the auction.

Taking all these factors into account, an estimated maximum purchase price for this coin could be in the range of 90 to 120 euros. This is based on the condition, previous hammer prices, and market trends. However, the final price will depend on the demand in the specific auction.