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. Starting Price: The starting price is 250 euros, which sets a baseline for the auction.

3. Price History: By looking at previous auction prices for similar coins, we can see that prices have varied significantly. For example, in past auctions, coins with condition ratings of 85 and 90 have reached hammer prices of up to 750 euros.

4. Sales Trends: The coin has been auctioned 64 times, of which it has sold 52 times. This indicates good demand and sustained interest in the coin.

5. Average Hammer Price: The average hammer price for similar coins is 73.19 euros, but given that this coin has a higher condition, it is reasonable to expect its hammer price to be above this average.

Taking all these factors into account, an estimated maximum purchase price could be in the range of 300 to 400 euros, considering that the condition is high and there is a price history suggesting that coins in similar conditions can reach higher prices.

Therefore, a reasonable maximum purchase price could be 350 euros.