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

1. Current Condition: The coin has a condition rating of 75 (MBC), indicating a medium-good quality. This can influence its value, as coins in better condition tend to fetch higher prices.

2. Auction History:
- The average hammer price for similar coins has been 64.35 euros.
- In previous auctions, we have seen hammer prices vary, with some reaching up to 180 euros under similar conditions (such as in the auction on December 12, 2024).

3. Starting Price and Estimates:
- The current starting price is 75 euros, which is slightly higher than the average starting price of 39.16 euros. This may indicate an expectation of greater interest in this auction.
- The estimated price for this auction is 75 euros, suggesting that the organizers believe the coin has significant value.

4. Sales Trends: The coin has been sold in 29 out of the previous 33 auctions, indicating good demand and consistent interest from collectors.

Based on these factors, an estimated maximum purchase price could be between 80 and 100 euros. This is because, although the starting price is 75 euros, the good condition and the history of hammer prices suggest that there could be competition in the auction, especially if there are collectors interested in this specific reference.

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