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

1. Current 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. Previous Auction Prices: By looking at previous auction prices for coins with a similar condition (95), we find that in recent auctions, the hammer prices have been:
- 5000 euros (2023-03-16)
- 3400 euros (2024-03-14)
- 3200 euros (2024-02-14)

3. Average Hammer Price: The average hammer price for this coin is 2276.47 euros, which is also a good indicator of the expected value.

4. Starting Price: The current starting price is 1500 euros, which is relatively low compared to previous hammer prices.

5. Auction Trends: The coin has been auctioned 21 times, with an 85.71% sell-through rate (18 out of 21). This suggests that there is consistent interest in the coin.

Based on these factors, an estimated maximum purchase price could be between 3000 and 4000 euros, considering that the highest recent hammer price was 5000 euros and that the coin's condition is high. However, since the starting price is 1500 euros, it is likely that the final hammer price will be closer to the lower end of this range, but still, it is reasonable to expect that a buyer would be willing to pay up to 4000 euros for it.