To estimate a maximum purchase price for the coin in question, we can analyze the provided data, especially the previous auction prices and the current condition of the coin.

1. Current Condition: The coin has a condition of 75 (VF), indicating that it is in a medium-low state of preservation. This may influence the price, as coins in better condition tend to reach higher prices.

2. Previous Auction Prices: By observing the auction prices of coins with similar conditions (75-80), we can see that:
- In several auctions, coins with a condition of 75 have reached hammer prices ranging from 12 to 90 euros.
- The average hammer price for coins with a condition of 80 has been approximately 30-40 euros.

3. Average Hammer Price: The average hammer price for this particular coin is 38.52 euros, which gives us a good reference.

4. Auction Trends: The coin has been auctioned 34 times, of which 25 have been successful sales. This indicates a consistent interest in the coin, which may increase its value.

5. Starting Price: The starting price is 15 euros, suggesting that the auctioneer expects moderate interest.

Based on these factors, an estimated maximum purchase price for this coin, considering its condition and previous hammer prices, could be between 40 and 60 euros. This is based on the fact that, although the condition is not the best, there is a price history suggesting it could reach a higher price in the current auction.

Therefore, an estimated maximum purchase price could be 50 euros.