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-low state of preservation. This generally affects the price, as coins in better condition tend to fetch higher prices.

2. Auction History:
- The average hammer price for this coin in the past has been 64.23 euros.
- Previous auctions with similar conditions (75) have had hammer prices that varied, but some examples can be observed:
- In 2020, a coin with a condition of 75 was sold for 20 euros.
- In 2019, another coin with a condition of 80 was sold for 25 euros.
- In 2022, a coin with a condition of 75 was sold for 35 euros.

3. Price Trends:
- The average starting price has been 47.61 euros, suggesting that sellers are looking for reasonable prices based on supply and demand.
- The coin has been auctioned 64 times, with an 87.5% sell-through rate, indicating consistent interest in this coin.

4. Data-Based Estimation:
- Given that the condition is 75 and considering previous hammer prices, an estimated maximum purchase price could be between 35 and 50 euros, depending on competition in the auction and the interest of other buyers.

Conclusion: An estimated maximum purchase price for this coin could be approximately 50 euros. This is based on the price history and the current condition of the coin.