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

1. Current Condition: The coin has a condition rating of 75 (MBC), indicating that it is in quite good shape. This can positively influence its value.

2. Current Starting Price and Previous Prices: The current starting price is 60 euros, and the average starting price in previous auctions is 82.14 euros. This suggests that the current starting price is relatively low compared to the historical average.

3. Previous Hammer Prices: The average hammer price in previous auctions is 107.25 euros. This indicates that, generally, coins of this reference tend to sell for above their starting price.

4. Sales History: Out of the 11 times it has been auctioned, it has sold 5 times, indicating moderate interest in the coin.

5. Price Trends: In the past, hammer prices have varied, but there are examples where the coin has sold for over 200 euros under similar conditions.

Based on these factors, an estimated maximum purchase price could be positioned between the average hammer price (107.25 euros) and a bit more, considering the good condition and interest in the coin.

Therefore, a reasonable estimated maximum purchase price could be around 120-130 euros. This allows for a margin for competition in the auction and reflects the historical value of the coin.