Based on the provided data, we can observe that the coin in question had a starting price of 12 euros in the most recent auction, with a conservation grade of 70 (MBC-). Additionally, it has been auctioned a total of 29 times in the past, out of which it was sold 26 times.

The average starting price of previous auctions has been 17.72 euros, while the average final price has been 24.75 euros. Regarding the previous prices of this coin, there is a variation in starting, estimated, and final prices over the years, ranging between 6 and 40 euros.

Considering these data, as well as the conservation of the coin and the price trends in previous auctions, we could estimate a maximum purchase price around 30-35 euros for this coin in the next auction. It is important to note that factors such as demand at the time of the auction and competition from other bidders can influence the final selling price.