Based on the data provided, we can observe that the coin in question has had a starting price in the current auction of 30 euros, with a conservation grade of 80 (MBC+). Additionally, it has been auctioned in the past on several occasions, with varying starting and final prices.

The average starting price of previous auctions has been 15.08 euros, while the average final price has been 24.88 euros. The coin has been sold in 8 out of the 11 previous auctions.

Considering the previous prices of the coin and its current conservation grade, as well as the fact that it has sold in the majority of previous auctions, we could estimate a maximum purchase price around 35-40 euros. This is based on the current starting price of 30 euros and taking into account the upward trend in final prices in previous auctions.

It is important to note that the final auction price will depend on various factors, such as demand at the time of the auction and the willingness of buyers to bid on the coin.