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 of 80 (MBC+), indicating that it is in relatively good shape. This generally translates to a higher price compared to coins with lower conditions.

2. Current Starting Price and Previous Prices: The current starting price is 75 euros, and the average hammer price in previous auctions is 166.69 euros. This suggests that, in general, coins of this reference tend to sell for a significantly higher price than their starting price.

3. Sales History: The coin has been auctioned 60 times, of which 55 have resulted in sales. This indicates good demand and consistent interest in this coin.

4. Previous Hammer Prices: Looking at previous hammer prices for coins with a similar condition (80), we can see that they have reached hammer prices of up to 220 euros in the past.

5. Recent Trends: In the most recent auctions, hammer prices have shown an increase, which could indicate an upward trend in the value of this coin.

Taking all these factors into account, an estimated maximum purchase price could be in the range of 200 to 250 euros. This is based on the hammer price history for coins of similar condition and the trend of increasing prices.

Therefore, a reasonable maximum purchase price could be 250 euros.