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 has a condition rating of 80 (MBC+), indicating that it is in relatively good shape. This suggests that its value should be above that of coins with lower conditions.

2. Previous Prices: By looking at the hammer prices of coins with similar conditions (around 80), we can see that the average hammer price in the past has been approximately 94.91 euros. However, it should be noted that the hammer price can vary depending on demand and other market factors.

3. Average Starting Price: The average starting price for this coin is 77.73 euros, which can also serve as a reference.

4. Recent Trends: In the most recent auctions, hammer prices have shown a trend of increasing, especially for coins in good condition. For example, in a recent auction, a coin with a similar condition sold for 105 euros.

5. Upcoming Auctions: There are 2 auctions scheduled in the coming days, which may increase competition and, therefore, the hammer price.

Taking all these factors into account, an estimated maximum purchase price for this coin could be around 110-120 euros. This is based on the condition, previous hammer prices, and market trends. However, it is important to stay alert to the dynamics of the auction and any competition that may arise.