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 in previous auctions is 86.29 euros.
- There are examples of hammer prices in the past that varied significantly, but some of the highest prices reached for coins in similar conditions have been up to 260 euros (in 2011) and 170 euros (in 2016).

3. Starting Price and Average Starting Price:
- The current starting price is 50 euros, which is relatively low compared to the average hammer price.
- The average starting price is 65.79 euros, suggesting that the market has valued this coin in a higher range in the past.

4. Recent Trends: In the most recent auction, the coin was offered with a starting price of 50 euros and was hammered at 80 euros, indicating that there is interest in the coin at higher prices.

Based on these factors, an estimated maximum purchase price could be in the range of 120 to 150 euros, considering that the condition is good and that the price history shows that coins in similar conditions have reached higher prices in the past.

Therefore, a reasonable maximum purchase price could be 150 euros.