To estimate a maximum purchase price for the coin in question, we can analyze several factors based on the provided data:

1. Current Condition: The coin has a condition rating of 85 (ebc-), indicating that it is in fairly good shape, but not the best possible condition.

2. Previous Auction Prices: By looking at previous auction prices for coins with a similar condition (85), we can see that they have varied. For example:
- In 2020, it was auctioned for 341 euros.
- In 2020, it was also auctioned for 380 euros.
- In 2015, it was auctioned for 295 euros.

3. Price Trends: The average auction price for this coin is 327.76 euros, suggesting that, in general, buyers are willing to pay around this amount.

4. Starting Price: The current starting price is 325 euros, which is reasonable and aligns with previous auction prices.

5. Competition Analysis: Given that there have been 88 previous auctions and 82 sales, this indicates a consistent interest in the coin, which may increase competition and, therefore, the price.

6. Maximum Price Estimate: Based on the average auction price and previous auction prices, a reasonable maximum purchase price could be in the range of 400 to 450 euros, considering that the condition is good and there is interest in the coin.

Therefore, an estimated maximum purchase price for this coin could be 450 euros.