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

1. Current Condition: The coin has a condition rating of 80 (MBC+), indicating that it is in quite good shape. This generally translates to a higher price compared to coins with lower conditions.

2. Auction History:
- The average hammer price from previous auctions is 166.25 euros.
- The last auction with a similar condition (85) had a hammer price of 400 euros, indicating that there is a market willing to pay high prices for coins in good condition.
- Previous auctions with lower conditions (70-75) have had hammer prices ranging from 100 to 140 euros.

3. Starting Price: The current starting price is 150 euros, which is a good starting point, but given the history of hammer prices, it may be reasonable to expect the final price to be higher.

4. Market Trends: Since the coin has sold in all previous occasions and has had a hammer price exceeding the starting price, this suggests there is consistent interest in this coin.

Based on these factors, an estimated maximum purchase price could be in the range of 200 to 250 euros. This is based on the history of hammer prices and the current condition of the coin. However, it is important to consider that bidder interest in the auction may influence the final price.