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 suggests that its value should be above that of coins with lower conditions.

2. Previous Prices: By looking at the hammer prices from previous auctions for coins with similar conditions, we can see that:
- In previous auctions with a condition of 70, the hammer prices have ranged between 25 and 80 euros.
- For conditions of 80 and 85, the hammer prices have been higher, reaching up to 150 euros.

3. Average Hammer Price: The average hammer price for this coin has been 97.38 euros, which is also a good indicator of the expected value.

4. Starting Price and Estimates: The current starting price is 40 euros, and the average starting price in the past has been 51.76 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 shown an increase, especially for coins in good condition.

Taking all these factors into account, an estimated maximum purchase price for this coin could be around 100-120 euros. This is based on the current condition, previous hammer prices, and market trends.