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

1. Coin Condition: The coin has a condition rating of 95 (EBC+), indicating 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 previous auction prices for coins with a similar condition (95), we can see that auction prices have varied but have reached significant figures. For example, in recent auctions, coins with a condition of 95 have reached hammer prices of up to 450 euros.

3. Average Hammer Price: The average hammer price for this coin is 290.62 euros, providing a reference point.

4. Starting Price: The starting price is 400 euros, indicating that the seller expects a reasonable price for the coin.

5. Recent Trends: In the most recent auctions, hammer prices have shown an upward trend, especially for coins in good condition.

Taking all these factors into account, an estimated maximum purchase price for this coin could be between 450 and 500 euros, considering that the condition is high and there is potential demand in the market. However, it is important to note that the final price will depend on the competition in the auction and the willingness of other bidders to pay.