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

1. Condition: The coin being auctioned has a condition of 95 (EBC+), which indicates that it is in very good shape. This generally increases its value compared to coins with lower conditions.

2. Previous auction prices: By observing the hammer prices of coins with similar conditions, we can see that in previous auctions, coins with conditions of 70 and 75 have reached hammer prices ranging from 122 to 480 euros. However, the coin in question has a higher condition, suggesting it could reach a higher price.

3. Starting price and average hammer price: The starting price is 900 euros, and the average hammer price in previous auctions is 391.5 euros. However, the starting price is significantly higher, which may indicate that considerable interest is expected in this coin.

4. Price trends: In the most recent auction of a coin with a condition of 95, the hammer price was 1600 euros, suggesting that there is a market willing to pay high prices for coins in excellent condition.

Taking all these factors into account, an estimated maximum purchase price for this coin could be in the range of 1200 to 1800 euros, considering that the condition is high and there are precedents for hammer prices in that range. However, given the starting price of 900 euros, it is possible that bidders may be willing to exceed that figure if demand is high.

Therefore, an estimated maximum purchase price could be 1600 euros.