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

1. Current Condition: The coin has a condition of 85 (ebc-), indicating that it is in quite good shape. This suggests that its value should be in the upper range of previous auctions.

2. Previous Prices: Looking at previous auction prices for coins with similar conditions:
- In 2016, a coin with a condition of 85 was auctioned for 90 euros.
- In 2024, a coin with a condition of 85 was auctioned for 220 euros.
- In 2023, a coin with a condition of 90 was auctioned for 100 euros.

3. Average Auction Price: The average auction price for this coin is 104.46 euros, which also indicates that the market value is in that range.

4. Starting Price: The starting price is 40 euros, which is relatively low compared to previous auction prices.

5. Sales Trends: The coin has been auctioned 16 times, of which 14 have sold, indicating good demand.

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 previous auction prices have been higher.

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