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

1. Current starting price: 200 euros.
2. Auction history: The coin has been auctioned 2 times in the past and sold on both occasions. This indicates interest and demand for the coin.
3. Average hammer price: 210 euros, which is the average price at which it has sold in previous auctions.
4. Condition: The coin has a condition rating of 80 (VF+), which is a good condition and may positively influence its value.
5. Average starting price in the past: 167.5 euros, which is lower than the current starting price, but the average hammer price is more relevant.

Given that the average hammer price is 210 euros and considering that the condition is good, an estimated maximum purchase price could be slightly above the average hammer price, but not too much, to avoid overpaying.

Therefore, an estimated maximum purchase price could be around 220 euros. This allows for some margin for competition in the auction, as the interest in the coin seems to be solid.