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 rating of 80 (VF+). This is an important factor, as coins in better condition tend to fetch higher prices.

2. Previous Auction Prices:
- In previous auctions, we have seen hammer prices that vary significantly. For example:
- In 2018, a coin with a condition of 95 sold for 2200 euros.
- In 2022, a coin with a condition of 95 sold for 2600 euros.
- In 2023, a coin with a condition of 90 sold for 950 euros.
- In 2020, a coin with a condition of 80 sold for 460 euros.

3. Price Trends:
- The average hammer price for this coin is 1041.22 euros, indicating that, in general, coins of this reference tend to sell for above 1000 euros, especially if they are in better condition.
- The condition of 80 has shown hammer prices ranging between 400 and 460 euros in previous auctions.

4. Starting Price: The starting price is 400 euros, which is a reasonable starting point.

5. Estimation: Given that the condition is 80 and considering the previous hammer prices, a maximum purchase price could be in the range of 600 to 800 euros. This is based on the fact that, although the condition is not the highest, there is interest in the coin, and the average hammer price suggests it could reach a higher value.

Therefore, an estimated maximum purchase price for this coin could be approximately 700 euros.