Based on the data provided, we can observe that the coin has had an average auction closing price of 28.25 euros in previous auctions. Additionally, the condition of the coin on this occasion is 70 (VF+).

Considering that the starting price is 12 euros and that the average starting price in previous auctions was 17.29 euros, we can see that the coin tends to increase in value in auctions.

Given that the condition of the coin is good (70 VF+), and taking into account the history of previous prices as well as the average closing price, we could estimate a maximum purchase price of around 30-35 euros for this coin in the next auction. It is important to note that the final price may vary depending on the demand at the auction and other factors that may influence the bidding.