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 of 80 (MBC+), indicating that it is in quite good shape. This generally translates to a higher price compared to coins in lower condition.

2. Previous Prices:
- At the 2022 auction, a coin with a condition of 85 sold for 210 euros.
- In 2019, a coin with an estimated condition of 90 sold for 130 euros.
- In 2014, although the condition is not specified, the final price was 110 euros.
- In 2020, a coin with a condition of 70 sold for 45 euros.

3. Average Hammer Price: The average hammer price for this coin is 110.2 euros, indicating that, in general, coins of this reference tend to reach prices around this figure.

4. Starting Price: The starting price is 40 euros, which is relatively low compared to previous hammer prices.

Given that the condition of the coin is good (80) and considering the previous hammer prices, an estimated maximum purchase price could be in the range of 150 to 210 euros, taking into account that condition is an important factor and that the average hammer price is 110.2 euros.

Therefore, a reasonable estimated maximum purchase price could be 150 euros. This allows for some margin for competition in the auction, given that the condition is better than in some of the previous auctions.