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

1. Coin Condition: The coin has a condition rating of 95 (S/C-), indicating that it is in very good shape. This generally translates to a higher price compared to coins with lower conditions.

2. Auction History:
- The average hammer price for similar coins has been 43.59 euros.
- In previous auctions, coins with a similar condition (95) have reached hammer prices of up to 120 euros (as seen in the auctions on 2020-09-17 and 2020-10-21).

3. Starting Price: The starting price is 40 euros, which is a good starting point, but given the history of hammer prices, it is likely that the final price will be significantly higher.

4. Recent Trends: In the most recent auctions, hammer prices for coins of similar condition have shown a range that can reach up to 100-120 euros.

Based on these factors, an estimated maximum purchase price for this coin could be between 90 and 120 euros, considering that the condition is high and there is a history of hammer prices that supports this estimate.

Therefore, a reasonable maximum purchase price could be 100 euros.