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

1. Condition: The coin has a condition rating of 95 (EF+), indicating that it is in very good shape. This generally translates to a higher price compared to coins with lower conditions.

2. Auction History:
- The average hammer price for similar coins in the past has been 33.29 euros.
- Previous auctions of this coin have shown hammer prices that vary, but there are examples of sales in the range of 55 to 91 euros for coins in condition 100, and lower prices for coins in condition 95.

3. Starting Price and Estimates:
- The current starting price is 15 euros, which is relatively low compared to previous hammer prices.
- The average starting price for similar coins is 27.76 euros.

4. Sales Trends: The coin has been auctioned 43 times, of which 29 have been sold, indicating good demand.

Based on these factors, an estimated maximum purchase price could be in the range of 50 to 70 euros, considering that the condition is high and that the hammer price history for similar coins supports this estimate.

Therefore, a reasonable maximum purchase price could be 65 euros.