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 in previous auctions is 139.92 euros, suggesting that, in general, coins of this reference tend to sell for significantly higher prices than their starting price.
- In past auctions, we have seen hammer prices that varied considerably, ranging from 48 euros to 950 euros, depending on the condition and other factors.

3. Starting Price and Average Starting Price:
- The current starting price is 60 euros, which is slightly lower than the average starting price of 65.71 euros. This could indicate a good opportunity for buyers.

4. Recent Trends: In the most recent auction, a coin with a condition of 75 sold for 90 euros, suggesting that the market is willing to pay higher prices for coins in good condition.

Based on these factors, an estimated maximum purchase price for this coin could be in the range of 120 to 150 euros. This is based on the auction price history and the current condition of the coin. However, since the market can be volatile and depends on demand at the time of the auction, it is advisable to be prepared to adjust the bid according to competition and the interest of other bidders.