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 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 of up to 245 euros (in 2018) and 340 euros (in 2021). This suggests that there is a market willing to pay high prices for coins in good condition.

3. Average Auction Price: The average auction price for this coin is 119.03 euros, providing a solid reference for the expected value.

4. Starting Price and Estimates: The current starting price is 110 euros, and the average starting price in previous auctions is 51.11 euros. This indicates that interest in this coin has increased, which could lead to a higher auction price.

5. Auction Trends: Given that there has been growing interest in recent auctions, and considering that it has sold in the past for significantly higher prices, it is reasonable to assume that the auction price could be in the upper range.

Taking all these factors into account, an estimated maximum purchase price for this coin could be between 200 and 300 euros, considering that interest and competition in the auction could drive the price beyond the historical average. However, a more conservative price could be around 180 euros, given the starting price and interest in the coin.