To estimate a maximum purchase price for the coin in question, let’s consider several factors:

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

2. Starting Price: The starting price is 6000 euros, which sets a baseline for the auction.

3. Auction History:
- In the past, it has been auctioned 3 times, of which it has sold 2 times and not sold 1 time.
- The previous hammer prices are 700 euros (2021), 850 euros (2022), and the last one has no hammer price, but it was estimated at 10000 euros with a starting price of 7000 euros.

4. Average Hammer Price: The average hammer price of 775 euros is quite low compared to the current starting price and the estimated prices in previous auctions.

5. Price Trends: The highest hammer price was 850 euros, suggesting that, despite the good condition, interest in this coin may not be as high as expected.

Given that the condition is high and the starting price is 6000 euros, but considering the hammer price history and the average hammer price, an estimated maximum purchase price could be set in a more conservative range.

Estimated Maximum Purchase Price: It may be reasonable to consider a maximum purchase price around 3000-4000 euros, as this reflects a balance between the good condition and the lower hammer price history. This also allows for some margin for competition in the auction.