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

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

2. Auction History:
- The average hammer price in previous auctions is 44.57 euros.
- The coin has been auctioned 35 times, of which it has sold 30 times, indicating good demand.
- In previous auctions, the hammer price has varied, but there are examples of sales that have reached up to 130 euros (in January 2023).

3. Starting Price and Estimates:
- The current starting price is 40 euros, which is slightly higher than the average starting price of 29.39 euros.
- The estimated price for this auction is 70 euros, suggesting expectations for the coin to reach a higher price.

4. Price Trends:
- Observing the hammer prices of coins with similar conditions, it seems that the price range can vary quite a bit, but higher prices have been seen in coins with conditions of 80 or more.

Based on these factors, an estimated maximum purchase price could be in the range of 70 to 130 euros, considering that the highest recorded hammer price was 130 euros. However, since the starting price is 40 euros and the average hammer price is 44.57 euros, a reasonable maximum purchase price could be approximately 80-100 euros. This would allow for competitive bidding in the auction without exceeding historical hammer prices for coins in similar conditions.