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 similar coins in the past has been 60.63 euros.
- In previous auctions, hammer prices have ranged from 25 euros to 170 euros, depending on the condition and other factors.
- The last auction with a similar condition (75) had a hammer price of 55 euros.

3. Starting Price and Estimates:
- The current starting price is 50 euros, which is reasonable given the price history.
- The average starting price of 47.5 euros also suggests that the market is willing to pay in that range.

4. Recent Trends:
- In the most recent auctions, hammer prices have shown a trend of being higher, especially for coins in better condition.

Based on these factors, an estimated maximum purchase price could be in the range of 70 to 80 euros. This is because, although the average hammer price is 60.63 euros, the condition of 75 and the history of higher prices suggest that buyers may be willing to pay a bit more for this particular coin.

Therefore, an estimated maximum purchase price would be 75 euros.