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. This suggests that its value should be above that of coins in worse conditions.

2. Previous Prices: By looking at previous auction prices, we can see that coins with similar conditions have reached auction prices that vary significantly. For example:
- A coin with a condition of 95 was auctioned for 800 euros.
- A coin with a condition of 90 was auctioned for 180 euros.
- A coin with a condition of 85 was auctioned for 75 euros (although the auction price of the last auction is not available).

3. Average Auction Price: The average auction price for this coin is 171.88 euros, which is also an important indicator.

4. Starting Price and Average Starting Price: The starting price is 60 euros, and the average starting price is 78 euros. This suggests that interest in the coin may be moderate, but not necessarily low.

5. Auction Trends: Given that there have been 10 previous auctions and all have resulted in sales, this indicates a consistent interest in the coin.

Based on these factors, an estimated maximum purchase price could be in the range of 150 to 200 euros, considering that the condition is good and the average auction price is 171.88 euros. However, since the condition is lower than the highest ratings, a more conservative price could be around 150 euros.

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