Based on the data provided, we can observe that the coin in question has had an average auction price of 35.34 euros in previous auctions. Additionally, its condition has been maintained at an average of 75 (MBC).

Considering that the coin will be auctioned in the coming days with a starting price of 25 euros and has had an average starting price of 24.1 euros in previous auctions, we can estimate that the final auction price could be around 40-45 euros.

Given that the coin has performed well in previous auctions and its condition is relatively high, we could consider a maximum estimated purchase price of around 45-50 euros. This could be a good starting point to participate in the auction and secure the acquisition of the coin.