To estimate a maximum purchase price for the coin in question, we can analyze the provided data, especially the previous auction prices and the current condition of the coin.

1. Current Condition: The coin has a condition of 80 (VF+). This is an important factor, as coins in better condition tend to reach higher prices at auctions.

2. Previous Auction Prices: By observing the auction prices of coins with similar conditions (around 80-85), we can see that the auction prices have varied, but generally, they have been in the range of 400 to 480 euros in recent auctions.

3. Price Trends: The average auction price for this coin is 395.96 euros, indicating that, on average, coins of this reference sell for a price close to this value.

4. Analysis of Recent Auction Prices: In the most recent auctions, the auction prices have been 401 euros (2022) and 480 euros (2024) for coins with a condition of 85, suggesting that the price may be increasing.

5. Final Estimate: Given that the condition of the coin is 80, and considering the previous auction prices and the upward trend, an estimated maximum purchase price could be around 450 euros. This value reflects a balance between the current condition and the auction prices of similar coins in the past.

Therefore, the estimated maximum purchase price for this coin would be 450 euros.