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

1. Condition of the coin: The coin has a condition rating of 85 (ebc-), which indicates that it is in quite good shape. In the past, coins with a similar condition have reached auction prices that vary, but they generally fall within a range of 40 to 60 euros.

2. Previous auction prices: By observing the auction prices of coins with a condition rating of 85, we can see that they have reached auction prices of up to 60 euros on several occasions. For example, in previous auctions, coins with a condition rating of 85 have sold for 40, 45, and 60 euros.

3. Average auction price: The average auction price for this coin is 47.86 euros, which also suggests that an auction price around this value is reasonable.

4. Starting price and estimated prices: The starting price is 25 euros, and the estimated price is 50 euros. This indicates that there is an expectation for the coin to sell for a price higher than the starting price.

5. Recent trends: In the most recent auctions, the auction prices have shown a trend of being in the range of 40 to 60 euros for coins of similar condition.

Based on these factors, an estimated maximum purchase price for this coin could be around 60 euros. This price reflects both the condition of the coin and historical auction prices, as well as current market expectations.