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

1. Condition: The coin has a condition rating of 85 (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:
- The average hammer price for similar coins has been approximately 2762.46 euros.
- In previous auctions, coins with a similar condition (85) have reached hammer prices that vary, but some examples are:
- 2365 euros in December 2020.
- 2700 euros in December 2017.
- 2000 euros in February 2023.

3. Starting Price: The current starting price is 2500 euros, suggesting that the seller has expectations of a hammer price along those lines.

4. Price Trends: Looking at the hammer prices from previous auctions, it seems that coins with a condition of 85 have had a hammer price range between 2000 and 2700 euros, with some exceptional cases exceeding 3000 euros.

Based on these factors, an estimated maximum purchase price could be around 3000 euros, considering that the condition is good and there is a trend for hammer prices to exceed 2500 euros in recent auctions. However, it is important to keep in mind that the market can be volatile and that other factors, such as demand at the time of the auction, will also influence the final price.