To estimate a maximum purchase price for the coin in question, we will consider several factors:

1. Coin Condition: The coin has a condition rating of 85 (MBC+/EBC-), indicating that it is in quite good shape. This generally translates to a higher price compared to coins with lower conditions.

2. Previous Prices: By looking at the auction prices of coins with similar conditions, we can see that coins in a condition rating of 85 have reached auction prices that vary but tend to be in the range of 100 to 300 euros, depending on demand and other factors.

3. Average Auction Price: The average auction price for this coin in the past has been 100.98 euros, providing a good reference point.

4. Current Starting Price and Recent Auction Prices: The current starting price is 40 euros, which is relatively low compared to previous auction prices. This suggests that there may be a good buying opportunity.

5. Market Trends: Since it has been auctioned 131 times and sold 116 times, the coin has a solid sales history, which may indicate consistent demand.

Based on these factors, an estimated maximum purchase price could be in the range of 150 to 250 euros. This is based on the coin's condition, auction price history, and market trends. However, it is important to note that the final price may vary depending on competition in the auction and demand at the time of sale.