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

1. Condition: The coin has a condition rating of 80 (MS+), 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 coin has been auctioned 5 times and has sold in all of them. This suggests that there is consistent interest in the coin, which may increase its value.

3. Previous Prices:
- In previous auctions, the hammer prices have varied, but the average hammer price is 206 euros.
- The last auction shows a hammer price of 220 euros, indicating that interest and value in the coin may be increasing.

4. Current Starting Price: The starting price is 200 euros, which is slightly lower than the previous average hammer price.

5. Market Trends: Since the average hammer price has been higher than the current starting price, this suggests that there could be competition in the auction that might drive the price up.

Taking all these factors into account, an estimated maximum purchase price could be around 250-270 euros. This is based on the demonstrated interest in previous auctions and the condition of the coin. However, it is important to remember that the final price will depend on the competition in the auction and the demand at that specific moment.