To estimate a maximum purchase price for the coin in question, we can analyze several factors:

1. Condition of the coin: The coin to be auctioned has a condition of 95 (EF+), which indicates that it is in very good shape. This generally translates to a higher price compared to coins with lower conditions.

2. Previous auction prices: By observing the hammer prices of coins with similar conditions (95 and 80), we can see that coins in EF+ condition have reached hammer prices of up to 925 euros in the past (as seen in the auction on 2018-04-25).

3. Starting price and average prices: The current starting price is 600 euros, which is significantly higher than the average starting price of 177.92 euros and the average hammer price of 330.55 euros. This suggests that the seller has high expectations for this auction.

4. Price trends: In recent auctions, hammer prices have shown an increase, especially for coins in good condition. For example, in the auction on 2024-06-25, coins with similar conditions sold for hammer prices of up to 1200 euros.

Based on these factors, an estimated maximum purchase price could be in the range of 800 to 1200 euros, considering that the coin has a high condition and that past hammer prices have been favorable. However, since the starting price is 600 euros, it is possible that buyers may be willing to pay a little more, but not necessarily up to the estimated maximum.

Therefore, a reasonable estimated maximum purchase price could be 1000 euros.