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 generally translates to a higher price compared to coins with lower conditions.

2. Previous Auction Prices:
- The average hammer price for this coin has been 128.56 euros.
- In previous auctions, coins with a similar condition (80) have reached hammer prices of up to 220 euros (as seen in the auction on November 24, 2020).

3. Starting Price and Average Starting Price:
- The current starting price is 60 euros, which is relatively low compared to the average hammer price.
- The average starting price has been 82.12 euros, suggesting that the current starting price could be attractive to buyers.

4. Sales Trends: The coin has been sold in 25 out of the last 26 auctions, indicating good demand.

5. Maximum Price Estimate: Given that the condition is good and considering previous hammer prices, a reasonable maximum purchase price could be in the range of 180 to 220 euros, based on the highest recorded hammer price for a coin of similar condition.

Therefore, an estimated maximum purchase price for this coin could be 200 euros. This is based on previous price trends and the current condition of the coin.