Based on the data provided, we can observe that the coin has had an average auction closing price of 152.01 euros in previous auctions. Additionally, the current condition of the coin is 70 (VF+), indicating that it is not in the best condition.

Considering that the starting price for the next auction is 150 euros and that the coin has been sold in the past for prices ranging between 110 and 180 euros, we could estimate a maximum purchase price of around 180 euros.

However, keep in mind that the closing price in previous auctions has reached up to 300 euros, so if you are willing to pay a bit more and considering the upward trend in closing prices, you could consider a maximum purchase price of around 220-250 euros to ensure success in the auction.