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

1. Coin Condition: The coin to be auctioned has a condition of 95 (EBC+), indicating that it is in very good shape. This generally translates to a higher price compared to coins with lower conditions.

2. Previous Auction Prices: By observing the hammer prices of coins with a similar condition (95) in previous auctions, we can see that:
- In the auction on 2019-03-14, a coin with a condition of 95 was sold for 150 euros.
- In the auction on 2020-12-17, a coin with a condition of 110 was sold for 700 euros, but this is an exceptional case.
- In the auction on 2022-03-17, a coin with a condition of 95 was sold for 320 euros.

3. Average Hammer Price: The average hammer price for this coin is 108.71 euros, providing an additional reference point.

4. Starting Price: The starting price is 125 euros, indicating that the seller expects a reasonable price for the coin.

5. Auction Trends: Given that the coin has been auctioned 61 times and has had a high sales percentage (57 out of 61), this suggests there is consistent interest in this coin.

Based on these factors, an estimated maximum purchase price could be in the range of 250 to 350 euros, considering that the condition is high and there are precedents of successful sales in that range. However, given the starting price of 125 euros, it is likely that the final hammer price will not significantly exceed this range unless there is intense competition among bidders.

Therefore, a reasonable maximum purchase price could be 300 euros.