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

1. Current Condition: The coin has a condition rating of 80 (MBC+), indicating that it is in quite good shape. This generally translates to a higher price compared to coins with lower conditions.

2. Auction History:
- The average hammer price for similar coins has been 100.39 euros.
- In previous auctions, coins with a similar condition (80) have reached hammer prices of up to 370 euros (as seen in the auction on 2018-11-07).
- The last auction with a condition of 80 had a hammer price of 85 euros (2023-02-28).

3. Starting Price and Average Starting Price:
- The current starting price is 60 euros, which is slightly higher than the average starting price of 56.25 euros. This suggests that the seller has expectations of a higher price.

4. Sales Trends: Out of the 27 times it has been auctioned, 24 have been sold, indicating good demand for this coin.

5. Previous Estimates: The estimated price for this auction is 80 euros, which can also serve as an indicator of what buyers are willing to pay.

Based on these factors, an estimated maximum purchase price could be between 100 and 130 euros, considering that the average hammer price has been 100.39 euros and there are precedents of higher prices in previous auctions. However, since the starting price is 60 euros, it is likely that buyers will be willing to bid more, especially if there is interest in the coin.

Therefore, a reasonable maximum purchase price could be 120 euros.