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

2. Auction History:
- It has been auctioned 9 times in the past, of which it has sold 6 times. This suggests there is consistent interest in the coin.
- The average hammer price in previous auctions is 45 euros, which can serve as a reference point.

3. Starting and Hammer Prices:
- The current starting price is 60 euros, which is higher than the average starting price of 34.22 euros. This may indicate that the seller is confident that the coin will reach a higher price due to its condition.
- In previous auctions, hammer prices have varied, but there are examples of sales reaching up to 50 euros for coins of similar condition.

4. Price Trends:
- In the most recent auctions, starting and estimated prices have been increasing, which may indicate an upward trend in the value of this coin.

Based on these factors, an estimated maximum purchase price could be in the range of 70 to 90 euros. This is because, although the starting price is 60 euros, the good condition and price history suggest it could reach a higher price at auction.

Therefore, a reasonable maximum purchase price could be 80 euros.