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

1. Current Condition: The coin has a condition of 75 (MBC), which indicates that it is in fairly good shape, but not of the best quality (FDC).

2. Auction History:
- The average hammer price in previous auctions is 72.54 euros.
- It has been auctioned 36 times, of which it has sold 19 times, indicating a sell-through rate of 52.78%. This suggests there is moderate interest in the coin.
- Previous hammer prices for coins with a similar condition (75) have varied, but there are examples of auctions reaching up to 140 euros (although this may be an exceptional case).

3. Starting Price and Average Starting Price:
- The current starting price is 40 euros, and the average starting price in the past has been 59.95 euros. This suggests that the current starting price is relatively low compared to the historical average.

4. Recent Trends: In the most recent auctions, hammer prices for coins with similar conditions have been in the range of 45 to 60 euros.

Based on these factors, an estimated maximum purchase price could be in the range of 70 to 90 euros. This is based on historical interest, current condition, and average hammer price. However, since the starting price is 40 euros, it could be a good buying opportunity if it can be acquired below this range.

Therefore, an estimated maximum purchase price could be 80 euros.