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

1. Current Condition: The coin has a condition rating of 85 (ebc-), indicating that it is in fairly good shape, but not the best possible condition.

2. Auction History:
- The average hammer price for coins of similar condition (85) has been approximately 1,600 to 1,800 euros in previous auctions.
- In recent auctions, the hammer price has reached up to 3,400 euros for coins in condition 95, indicating that there is an active market willing to pay high prices for coins in good condition.

3. Starting Price and Average Hammer Price:
- The current starting price is 1,500 euros, which is a reasonable starting point.
- The average hammer price in the past has been 1,978.34 euros, suggesting that buyers are willing to pay more than the starting price.

4. Market Trends:
- The coin has been auctioned 39 times, with a 77% sell-through rate, indicating consistent interest in this coin.
- The price trend appears to be increasing, especially for coins in higher condition.

Based on these factors, an estimated maximum purchase price for this coin could be between 2,000 and 2,500 euros. This is based on the auction price history for coins of similar condition and market interest. However, since the condition is not the highest, it is wise not to exceed the upper range too much.

Therefore, a reasonable maximum purchase price could be 2,200 euros.