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

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

2. Auction History:
- The average hammer price for similar coins in the past has been 46.77 euros.
- Previous auctions of this coin have shown hammer prices that vary, but generally, hammer prices for similar conditions (75-80) have been in the range of 35 to 70 euros.

3. Starting Price and Estimates:
- The current starting price is 15 euros, which is relatively low compared to previous hammer prices.
- The average starting price has been 23.59 euros, suggesting that the market is willing to pay more than the starting price.

4. Recent Trends:
- In the most recent auctions, hammer prices have been in the range of 70-86 euros for similar conditions.

Based on these factors, an estimated maximum purchase price for this coin could be between 70 and 90 euros, considering that the condition is good and that the hammer price history suggests collectors are willing to pay more for coins in similar conditions.

Therefore, a reasonable maximum purchase price could be 80 euros.