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

1. Starting Price: 150 euros.
2. Condition: The coin has a condition rating of 70 (VF-), indicating that it is in relatively good shape.
3. Auction History:
- In 2016, the coin was auctioned with a starting price of 110 euros and sold for 170 euros.
- In 2024, it was auctioned with a starting price of 75 euros and sold for 320 euros, although the condition in this case was 30, suggesting that the coin was in much worse shape.

4. Average Hammer Price: 245 euros, indicating that, in general, coins of this reference tend to reach higher prices at auctions.

Given that the condition of the current coin is significantly better than that of the 2024 auction, and considering the average hammer price and price history, we can estimate that the maximum purchase price could be in a range above the starting price.

Taking all these factors into account, an estimated maximum purchase price could be between 250 and 300 euros, given that the condition is good and the auction history suggests that buyers are willing to pay more for coins in better condition.

Therefore, a reasonable maximum purchase price could be approximately 280 euros.