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 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 34.9 euros.
- In previous auctions, coins with a similar condition (around 85) have reached hammer prices that vary, but some examples are:
- 35 euros (2019-09-19)
- 42 euros (2017-09-21)
- 30 euros (2021-06-22)
- 50 euros (2023-01-18)

3. Starting Price and Estimated Price:
- The starting price is 25 euros, and the estimated price is 50 euros. This suggests that there are expectations for the coin to sell at a higher price.

4. Recent Trends: In the most recent auctions, hammer prices have shown a trend of being higher, especially for coins in good condition.

Based on these factors, an estimated maximum purchase price for this coin could be between 40 and 55 euros. This is based on the historical hammer prices for coins of similar condition and the current estimated price.

Therefore, a reasonable maximum purchase price could be 50 euros.