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. Starting Price and Average Hammer Price: The starting price is 2200 euros, and the average hammer price in previous auctions is 2934.31 euros. This suggests that, on average, similar coins have reached prices above the starting price.

3. Sales History: The coin has been auctioned 42 times, of which 35 have been successful sales. This indicates good demand and consistent interest in the coin.

4. Previous Prices: Looking at previous hammer prices for coins with a similar condition (85), it can be seen that they have reached hammer prices that vary, but many are above 3000 euros. For example, in recent auctions, they have sold for 3400 euros and 3600 euros.

5. Market Trends: The general trend seems to be that coins in condition 85 are reaching hammer prices ranging between 3000 and 4000 euros, depending on the demand at the time of the auction.

Based on these factors, an estimated maximum purchase price for this coin could be around 3500 euros. This is based on the hammer price history and the current condition of the coin. However, it is important to note that the final price may vary depending on the competition in the auction and the demand at that specific moment.