Based on the data provided, we can observe that the coin in question has had an average starting price in previous auctions of 13.89 euros and an average closing price of 23.67 euros. Additionally, it has been auctioned 10 times in the past, always selling, with a conservation grade of 80 (MBC+).

When analyzing the previous prices of this coin, we can see that it has had a varied price range, with estimates ranging from 15 euros to 30 euros, and closing prices that have reached up to 40 euros on one occasion.

Given that the coin is in a conservation grade of 80 (MBC+), and considering its price history, we could estimate a maximum purchase price around 35-40 euros. It is important to consider that this is just an estimate and that the final price in an auction may vary depending on various factors such as demand at that specific time.