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 90 (EBC), indicating that it is in quite good shape. This generally translates to a higher price compared to coins with lower conditions.

2. Auction History: By looking at previous hammer prices for coins with a similar condition (90 or 95), we can see that hammer prices have varied. For example, in past auctions, coins with a condition of 90 have reached hammer prices of up to 130 euros.

3. Average Hammer Price: The average hammer price for this coin is 69.25 euros, which provides a baseline for estimating the maximum price.

4. Recent Trends: In the most recent auctions, hammer prices have shown an increase, suggesting that demand for this coin may be growing.

5. Starting Price: The starting price is 40 euros, which is relatively low compared to previous hammer prices.

Taking all these factors into account, an estimated maximum purchase price for this coin could be around 120-140 euros, as this price reflects both the condition and the historical hammer prices in previous auctions.