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

1. Current Condition: The coin has a condition rating of 75 (MBC), indicating that it is in quite good shape. This generally translates to a higher price compared to coins in lower condition.

2. Auction History:
- The coin has been auctioned 15 times, of which it has sold 6 times. This suggests that there is moderate interest in the coin.
- The average starting price in previous auctions is 32.81 euros, and the average hammer price is 36.33 euros. This provides context regarding the market value of the coin.

3. Previous Prices:
- In recent auctions, the starting price has been 60 euros with an estimated price of 90 euros, indicating expectations for the coin to reach a higher price.
- In the most recent auction (2023-02-16), the starting price was 60 euros and the estimated price was 90 euros, suggesting that the market is willing to pay more for coins in good condition.

4. Price Trends:
- Looking at previous hammer prices, the highest recorded price was 50 euros in a 2016 auction, but in more recent auctions, the estimated price has increased, which could indicate an upward trend.

Based on these factors, an estimated maximum purchase price could be in the range of 70 to 90 euros, considering that the condition is good and there is growing interest in the coin. A price of 80 euros could be a reasonable starting point for an offer, as it falls in the middle of this range and reflects both the condition and recent market trends.