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 with lower conditions.

2. Previous Auction Prices: By looking at previous auction prices for coins with similar conditions (around 80), we can see that they have reached auction prices that vary, but some examples are:
- 80 (MBC): Auctioned for 60 (2018-10-16)
- 85 (MBC+): Auctioned for 150 (2018-10-17)
- 75 (MBC): Auctioned for 35 (2019-07-03)

3. Average Auction Price: The average auction price for this coin is 80.88 euros, which is also a good indicator of the expected value.

4. Starting Price and Average Starting Price: The current starting price is 40 euros, and the average starting price is 45.88 euros. This suggests that the market is willing to pay more than the starting price.

5. Recent Trends: The coin has been auctioned 112 times in the past, with an 84.82% sell-through rate (95 out of 112). This indicates good demand.

Based on these factors, an estimated maximum purchase price could be in the range of 100 to 120 euros, considering that the condition is good and the average auction price is 80.88 euros. This also takes into account the possibility that buyers may be willing to pay a bit more for a coin in good condition.

Therefore, an estimated maximum purchase price could be 110 euros.