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 being auctioned has a condition rating of 95 (EBC+), indicating that it is in very good condition. This generally translates to a higher price compared to coins with lower conditions.

2. Starting Price: The starting price is 600 euros. This is a good starting point, but not necessarily the final price.

3. Auction History:
- The average hammer price for similar coins is 320.2 euros, but this can vary significantly depending on the condition.
- In the past, coins with similar conditions have reached hammer prices that exceed the current starting price. For example, in previous auctions, coins with conditions of 85 have sold for 700 euros, while others sold for lower prices but with inferior conditions.

4. Price Trends: By observing the hammer prices of coins with conditions ranging from 80 to 95, we can see a wide range. Coins in similar conditions have reached hammer prices ranging from 240 euros to 800 euros.

5. Final Estimate: Given that the coin has a condition rating of 95 and considering the history of hammer prices, an estimated maximum purchase price could be between 800 and 1000 euros. This is based on the fact that coins in similar conditions have achieved high hammer prices in the past.

Therefore, an estimated maximum purchase price for this coin could be 800 to 1000 euros.