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 fairly good shape, but not of the highest quality (FDC).

2. Auction History:
- The average hammer price for similar coins in the past has been 86.89 euros.
- Looking at the hammer prices of coins with a similar condition (around 75), we can see that they have reached varying hammer prices, but some examples are:
- 60 euros (2020-12-15)
- 65 euros (2020-02-12)
- 75 euros (2019-12-11)
- 70 euros (2022-11-29)
- 130 euros (2023-01-18, although this coin has a condition of 75, the price is higher due to demand).

3. Starting Price and Average Starting Price:
- The starting price is 50 euros, and the average starting price is 55.58 euros. This suggests that the market is willing to pay a little more than the starting price.

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

Based on these factors, an estimated maximum purchase price for this coin could be between 90 and 110 euros. This is based on the historical hammer prices for coins of similar condition and the price trend in recent auctions.

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