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

1. Current Condition: The coin has a condition rating of 75 (MBC), indicating that it is in an acceptable state, but not among the best qualities.

2. Starting Price: The starting price is 60 euros, which sets a baseline for the auction.

3. Sales History: The coin has been auctioned 38 times in the past, of which it has sold 28 times. This indicates good demand and a relatively solid sales history.

4. Average Prices: The average starting price in previous auctions is 103.28 euros, and the average hammer price is 164.14 euros. This suggests that, in general, coins of this reference tend to sell for significantly higher prices than the current starting price.

5. Previous Prices: Looking at previous hammer prices for coins with a similar condition (75), we find that they have reached hammer prices of up to 100.87 euros and 66.8 euros in past auctions.

6. Recent Trends: In the most recent auctions, hammer prices for coins with similar conditions have been in the range of 75 to 100 euros.

Based on these factors, an estimated maximum purchase price for this coin could be in the range of 90 to 120 euros. This is because, although the condition is not the highest, the sales history and previous hammer prices suggest that there is potential to reach higher prices at auction.

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