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

1. Coin 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 similar conditions (around 70-80), we can see that the hammer prices have varied. For example:
- In previous auctions, coins with a condition of 70 have reached hammer prices of up to 90 euros.
- Coins with a condition of 80 have reached hammer prices of up to 150 euros.

3. Average Hammer Price: The average hammer price for this coin is 88.42 euros, which is also a good indicator of the expected value.

4. Recent Trends: In the most recent auctions, hammer prices have shown an increase, especially for coins in good condition.

Based on these factors, an estimated maximum purchase price for this coin could be in the range of 100 to 120 euros. This is based on the coin's condition, the history of hammer prices, and current market trends.