To estimate a maximum purchase price for the coin in question, we can analyze the provided data, especially the current condition of the coin (75, MBC) and the hammer prices from previous auctions.

1. Condition: The coin has a condition of 75 (MBC), indicating that it is in fairly good shape, but not the best possible condition.

2. Previous hammer prices:
- In previous auctions, hammer prices have varied, but we can observe that, in general, hammer prices have ranged from 15 to 75 euros, depending on the condition.
- For example, a coin with a condition of 80 was sold for 40 euros, and another with a condition of 90 was sold for 75 euros.

3. Price trends:
- The average hammer price for this coin is 33 euros, which can serve as a good indicator of the expected value.
- The last auction with a similar condition (75) had a hammer price of 40 euros.

4. Estimation:
- Given that the condition of the coin is 75 and considering the previous hammer prices, an estimated maximum purchase price could be in the range of 40 to 50 euros. This is based on the fact that the coin is in acceptable condition and that previous hammer prices have shown that coins in similar conditions have reached those values.

Therefore, an estimated maximum purchase price for this coin could be 45 euros.