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

1. Current Condition: The coin has a condition rating of 75 (MBC), indicating that it is in quite good shape. This generally translates to a higher price compared to coins with lower conditions.

2. Auction History: The coin has been auctioned 38 times and has had an average hammer price of 42 euros. This is a good indicator of its market value.

3. Previous Prices: Looking at previous hammer prices, we can see that on several occasions it has reached hammer prices of 60 euros or more, especially in similar conditions.

4. Recent Trends: In the most recent auctions, hammer prices have ranged from 40 to 80 euros, suggesting that there is a steady demand for this coin.

Based on these factors, an estimated maximum purchase price could be around 60-70 euros, given that the condition is good and the price history supports this estimate. However, it is important to keep in mind that the final price may vary depending on competition in the auction and other market factors at the time of sale.