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

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

2. Auction History: By looking at previous hammer prices for coins with a similar condition (75), we can see that in past auctions, the hammer prices have varied. For example:
- In 2019, a coin with a condition of 75 was sold for 35 euros.
- In 2017, another coin with the same condition sold for 160 euros, although the starting price was higher.
- In 2022, a coin with a condition of 80 was auctioned for 100 euros.

3. Average Hammer Price: The average hammer price for this coin is 58.24 euros, which can serve as a good indicator of the expected value.

4. Starting Price and Estimated Prices: The current starting price is 15 euros, and the average starting price in the past has been 26.09 euros. This suggests that the market is willing to pay more than the starting price.

5. Recent Trends: In the most recent auctions, hammer prices have been higher, especially for coins in good condition.

Taking all these factors into account, an estimated maximum purchase price for the coin could be between 70 and 100 euros, considering that the condition is good and there is a history of hammer prices that supports this estimate. However, since the market can be volatile, it is advisable to keep an eye on the auction and adjust the bid accordingly.