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

1. Current Condition: The coin has a condition of 85 (ebc-), which indicates 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 of similar coins in the past is 68.73 euros.
- In previous auctions, we have seen hammer prices that varied significantly, but there are examples of sales in the range of 75 to 160 euros for coins with similar conditions.

3. Starting Price and Average Starting Price:
- The current starting price is 40 euros, which is relatively low compared to the average hammer price.
- The average starting price of 49.79 euros also suggests that the current starting price is attractive.

4. Sales Trends: Since this coin has sold every time it has been auctioned (15 out of 15), this indicates a consistent demand.

5. Comparison with Previous Prices:
- In the most recent auction (2023-03-16), a coin with a condition of 95 sold for 150 euros. This suggests that a coin with a condition of 85 could reach a lower, yet still significant, price.

Based on these factors, an estimated maximum purchase price for this coin could be in the range of 100 to 130 euros. This is based on the condition, the hammer price history, and the demand observed in previous auctions.