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 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. Current and Previous Prices: The current starting price is 90 euros. In previous auctions, we have seen hammer prices that vary, but there are examples of hammer prices exceeding 200 euros for coins with similar conditions. For instance, in the auction on March 16, 2023, a coin with a condition of 100 was sold for 240 euros.

3. Average Hammer Price: The average hammer price for similar coins is 100.2 euros, suggesting that the market is willing to pay around this amount.

4. Auction Trends: The coin has been auctioned 65 times in the past, with an 89% sell-through rate. This indicates good demand and sustained interest in this reference.

5. Comparison with Previous Prices: In previous auctions, we have seen hammer prices reaching up to 270 euros for coins of similar condition.

Taking all these factors into account, an estimated maximum purchase price for this coin could be between 200 and 250 euros, considering its good condition and the price trends in previous auctions. A price of 240 euros could be a reasonable target, given that it has been reached in recent auctions for high-condition coins.