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 in lower conditions.

2. Historical Prices: Looking at previous auction prices, we can see that the coin has reached hammer prices of up to 3400 euros in similar conditions. However, most hammer prices are between 2000 and 3000 euros.

3. Average Hammer Price: The average hammer price for this coin is 2037.15 euros, providing a good reference for the expected value.

4. Recent Trends: In the most recent auctions, hammer prices have varied, but they have remained in a range that suggests demand is still strong.

5. Starting Price: The starting price is 25 euros, which is significantly lower than previous hammer prices, suggesting there is potential for an increase in the hammer price.

Given all this, an estimated maximum purchase price could be in the range of 2000 to 2500 euros, considering that the condition is good and that the price history shows that coins in similar conditions have reached higher prices.

Therefore, a reasonable maximum purchase price could be 2500 euros.