To estimate a maximum purchase price for the coin in question, we will consider several factors, including the current condition of the coin, previous auction prices, and the average auction price.

1. Condition of the coin: The coin has a condition rating of 80 (VF+). This indicates that it is in relatively good shape, which may positively influence its price.

2. Previous auction prices:
- In previous auctions, coins with a similar condition (80) have reached auction prices that vary considerably. For example, in a 2020 auction, a coin with a condition of 80 sold for 190 euros.
- There are also examples of coins with conditions of 85 and 90 that have sold for higher prices, suggesting that the market values the quality of the coin positively.

3. Average auction price: The average auction price for this coin is 98.9 euros, which provides a good reference point.

4. Starting price: The starting price is 25 euros, which is quite low compared to previous auction prices.

5. Market trends: Given that it has been auctioned 1,295 times and sold 999 times, there is good demand for this coin, which may increase its price at auction.

Based on these factors, an estimated maximum purchase price could be between 150 and 200 euros, considering that the condition is good and there are precedents of higher auction prices for coins in similar conditions. However, the final price will depend on the competition in the auction and the willingness of other bidders to pay.