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

1. Current 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 in worse conditions.

2. Auction History:
- The average hammer price for this coin in the past is 84.54 euros.
- In previous auctions, we have seen hammer prices that varied significantly, ranging from 25 euros to 380 euros, depending on the condition and other factors.
- The most recent auction (2022) had a hammer price of 120 euros, indicating a growing interest in this coin.

3. Starting Price and Average Starting Price:
- The current starting price is 50 euros, which is below the average starting price of 55.67 euros. This could indicate a good buying opportunity.

4. Recent Trends: The trend in hammer prices has shown an increase in recent years, suggesting that the value of the coin may continue to rise.

Taking all these factors into account, an estimated maximum purchase price for this coin could be around 120-140 euros, based on the most recent hammer price and the historical hammer prices for coins in similar conditions. This also considers the growing interest in the coin and its good condition.