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

1. Current Condition: The coin has a condition 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. Historical Prices: By looking at previous auction prices for coins with a similar condition (80-85), we can see that auction prices have varied. For example, in past auctions, coins with a condition of 80 have reached hammer prices of up to 63 euros, while others with a condition of 85 have gone up to 140 euros.

3. Average Hammer Price: The average hammer price for this coin is 121.02 euros, which provides a good reference point.

4. Starting Price and Average Starting Price: The current starting price is 40 euros, and the average starting price is 80.76 euros. This suggests that the market is willing to pay more than the starting price, especially for coins in good condition.

5. Recent Trends: Recent trends in auctions show that coins in similar conditions have seen an increase in hammer prices, which could indicate growing interest in this type of coin.

Based on these factors, an estimated maximum purchase price for the coin in question could be between 120 and 150 euros, considering that the condition is good and that interest in such coins seems to be on the rise. However, it is important to keep in mind that the final price will depend on the competition in the auction and the specific demand at the time.