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

1. Starting Price: 60 euros.
2. Condition: The coin has a condition rating of 30 (BC+), indicating that it is not in the best condition. This may affect its value compared to coins in better condition.
3. Auction History:
- In 2017, the coin was auctioned with a starting price of 50 euros and sold for 220 euros, indicating strong interest and a final price significantly higher than the starting price.
- In 2016, the starting price was 25 euros and it sold for 40 euros, showing more moderate interest.

4. Average Hammer Price: 130 euros, which is a good indicator of the market value of the coin.

Given that the coin has a starting price of 60 euros and considering the auction history, the average hammer price, and the condition, an estimated maximum purchase price could be in a range between the average hammer price and the highest observed hammer price.

Taking all this into account, an estimated maximum purchase price could be around 150 euros. This reflects moderate interest, considering the condition of the coin and the auction history.