Based on the provided data, we can observe that the coin in question has had a starting price in the current auction of 25 euros and is in a conservation grade of 30 (BC+). Additionally, several auctions have been conducted in the past with varying starting and final prices.

The average starting price of previous auctions has been 38.19 euros, while the average final price has been 52.64 euros. The coin has been auctioned a total of 25 times in the past, sold in 23 instances and not sold in 2 instances.

Some of the previous prices for this coin have ranged between 15 euros and 75 euros, with price estimates ranging from 25 euros to 125 euros. The conservation grades of coins auctioned in the past have varied, ranging from 30 to 80.

Given that the coin is in a conservation grade of 30 (BC+), and considering the previous prices and the trend of final prices, as well as the fact that it has sold in the majority of previous auctions, we could estimate a maximum purchase price of around 60-70 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.