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 30 (BC+). Additionally, it has been auctioned in the past on several occasions, with varying starting and final prices.

The average starting price of this coin in previous auctions has been 37.5 euros, while the average final price has been 78.5 euros. In past auctions, it has been sold 6 times and not sold 2 times.

When analyzing the previous prices of this coin, we can see that it has had a wide price range, with estimates ranging from 20 euros to 150 euros. The conservation value has also varied in each auction.

Given that the coin is in a conservation grade of 30 (BC+), and considering the previous prices and the average final price, as well as the fact that it has sold in most of the previous auctions, we could estimate a maximum purchase price around 80-90 euros for this coin in the current auction. It is important to note that the final price may vary depending on the demand at the auction and other external factors.