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

1. Coin Condition: The coin has a condition of 80 (MBC+), which indicates that it is in fairly good shape, but not of the best quality (FDC).

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 was sold for 190 euros.
- There are also examples of coins with a condition of 85 that have sold for prices in the range of 40 to 60 euros.

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, suggesting that there is considerable room for the auction price to be higher.

5. Market Trends: Since the coin has been auctioned 1,295 times and has had a high sales percentage (971 out of 1,295), this indicates a steady demand.

Based on these factors, an estimated maximum purchase price for this coin could be in the range of 150 to 200 euros, considering that the condition is good and there are precedents for higher auction prices in the past. However, since the market can fluctuate, it is advisable to keep an eye on the auction and adjust the bid accordingly.