Based on the provided data, we can observe that the coin in question had an initial price of 12 euros in this auction, with a conservation grade of 30 (BC+). Additionally, it has been auctioned in the past on several occasions, with final prices ranging between 25 and 85 euros.

The average final price of this coin in previous auctions has been 51.57 euros, with an average starting price of 39 euros. However, in the last recorded auction, the coin was sold for 35 euros, below the estimated price.

Given that the conservation grade of the coin is 30 (BC+), and considering the previous final prices, as well as the starting price in this auction, we could estimate a maximum purchase price around 60 euros. It is important to note that this is just an estimate and the final price may vary depending on the demand in the current auction.