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 quite good shape. This generally translates to a higher price compared to coins with lower conditions.

2. Auction History:
- The average hammer price for coins of this reference is 48.82 euros.
- In previous auctions, we have seen hammer prices that vary, but there are examples of sales reaching up to 120 euros (as in the May 2024 auction).

3. Starting Price and Average Starting Price:
- The current starting price is 40 euros, which is slightly higher than the average starting price of 27 euros. This may indicate an expectation of greater interest in this auction.

4. Sales Trends: The coin has been sold in 11 of the last 13 auctions, suggesting a consistent interest in this reference.

5. Comparison with Previous Prices:
- In the May 2024 auction, a coin with the same condition was sold for 120 euros, setting a high precedent.

Taking all these factors into account, an estimated maximum purchase price could be in the range of 80 to 120 euros. This is based on the good condition of the coin, the demonstrated interest in previous auctions, and the highest recorded hammer price.

Therefore, a reasonable estimated maximum purchase price could be 100 euros.