Based on the provided data, we can observe that the coin in question has had a starting price in the current auction of 12 euros, with a conservation grade of 25 (BC). Additionally, it has been auctioned in the past 19 times, sold in 15 instances, and not sold in 4 instances.

The average starting price in previous auctions has been 35.11 euros, while the average final price has been 44.47 euros. Previous prices for this coin vary, with estimates ranging from 20 euros to 125 euros, depending on the auction date and conservation grade.

Given that the coin is in a conservation grade of 25 (BC) and considering the previous auction prices of similar coins, as well as the current starting price, we could estimate a maximum purchase price around 50-60 euros. It is important to consider that the final price will depend on the demand in the current auction and other potential buyers interested in the coin.