To estimate a maximum purchase price for the coin in question, let's consider several factors:

1. Condition: The coin has a condition of 85 (ebc-), which indicates that it is in fairly good shape, but not the best possible condition. This can influence the price, as coins in better condition tend to fetch higher prices.

2. Auction history:
- The average hammer price for coins of similar condition (85) has been approximately 3,400 to 5,500 euros in previous auctions.
- The last auction with a condition of 85 had a hammer price of 3,000 euros, suggesting that interest in this coin may be declining or that the market is adjusting.

3. Starting price and previous prices:
- The current starting price is 2,500 euros, which is relatively low compared to previous hammer prices.
- The average hammer price in the past has been 5,231.25 euros, indicating that there is potential for an increase in the hammer price.

4. Market trends: Since there are no auctions scheduled in the coming days, this could influence demand and price.

Based on these factors, an estimated maximum purchase price could be in the range of 4,000 to 5,000 euros, considering that the condition is good and that the price history suggests there is a market willing to pay more for this coin. However, given the starting price and the current context, a more conservative price could be around 4,500 euros as a reasonable target.