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

1. Current Grade: The coin has a grade of 75 (MS), indicating that it is in fairly good condition, but not of the highest quality (PR).

2. Previous Auction Prices: By looking at previous auction prices for coins with a similar grade (75), we can see that they have reached auction prices that vary considerably. For example:
- In previous auctions, coins with a grade of 75 have reached auction prices of up to 300 euros.
- The average auction price for coins of similar grade seems to be in the range of 150 to 250 euros.

3. Average Auction Price: The average auction price for this coin is 204.35 euros, which is also a good indicator of the expected value.

4. Starting Price: The starting price is 60 euros, suggesting that there is considerable room for the auction price to be higher.

5. Market Trends: Given that the coin has been auctioned 206 times and has had a sell-through rate of 94.66% (195 out of 206), this indicates consistent demand.

Based on these factors, an estimated maximum purchase price for this coin could be in the range of 250 to 300 euros. This is based on the analysis of previous auction prices and the current grade of the coin.