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 fairly good shape, but not the best possible condition.

2. Auction History:
- The average hammer price for this coin in the past has been 86.91 euros.
- In previous auctions, hammer prices have varied significantly, with some reaching up to 400 euros in higher condition grades (95).
- The last auction of this coin with a similar condition (85) had a hammer price of 190 euros.

3. Starting Price and Estimates:
- The current starting price is 30 euros, which is relatively low compared to the average hammer price.
- The average starting price in the past has been 50.29 euros, suggesting that the current starting price could be attractive to buyers.

4. Recent Trends:
- The coin has been auctioned 54 times, of which 49 have been successful sales, indicating good demand.
- The coin will be auctioned in the coming days, which may increase interest and competition among buyers.

Based on these factors, an estimated maximum purchase price could be in the range of 100 to 150 euros, considering that the condition is good and that the price history shows that coins in similar conditions have reached higher prices. However, given the starting price of 30 euros, some buyers may be willing to pay more, especially if there is interest in the auction.

Therefore, a reasonable maximum purchase price could be 120 euros.