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 80 (MBC+), indicating that it is in quite good shape. This can positively influence its value.

2. Starting Price and Average Hammer Price: The starting price is 125 euros, and the average hammer price in previous auctions is 123.89 euros. This suggests that the starting price is aligned with the historical value of the coin.

3. Auction History: The coin has been auctioned 8 times, of which it has sold 7. This indicates good demand and consistent interest in the coin.

4. Previous Prices: Looking at previous hammer prices, the highest recorded price was 375 euros in 2013, although this may be an exceptional case. More recent and relevant hammer prices (such as 64.72 euros in 2015 and 110 euros in 2020) are more representative of the current value.

5. Market Trends: Given that the average hammer price is 123.89 euros and considering that the current condition is good, it is reasonable to think that the price could be in a similar or slightly higher range.

Taking all these factors into account, an estimated maximum purchase price could be between 150 and 200 euros. This would allow for competitive bidding in the auction without exceeding the historical hammer value and considering the good condition of the coin.