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

1. Coin 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. Previous Auction Prices: By observing the hammer prices of coins with similar conditions (80 and 85), we can see that the hammer prices have varied considerably. For example:
- In 2020, a coin with a condition of 80 sold for 110 euros.
- In 2018, another coin with a condition of 80 sold for 80 euros.
- In 2022, a coin with a condition of 80 sold for 213 euros.

3. Average Hammer Price: The average hammer price for this coin is 165.94 euros, which gives us a good reference for what buyers are willing to pay.

4. Starting Price and Estimates: The starting price is 60 euros, and the average starting price is 57.62 euros. This suggests that the starting price is reasonable and could attract buyers.

5. Auction Trends: Given that it has been auctioned 70 times in the past and sold 63 times, this indicates good demand for this coin.

Based on these factors, an estimated maximum purchase price could be in the range of 200 to 300 euros, considering that the condition is good and there is a history of hammer prices that supports this estimate. However, since the market can be volatile, it is advisable to keep an eye on the auction and adjust the bid according to the competition.