Based on the data provided, we can observe that the coin in question has had a varied auction history in terms of starting and final prices. The coin's condition is in a fairly good state, with a grade of 85 (ebc-).

The starting price for the upcoming auction is 30 euros, and the average final auction price in previous auctions has been 52.17 euros. Additionally, it has been auctioned a total of 40 times in the past, with a sales percentage of 62.5% (25 times sold out of 40 auctions).

Taking into account this data, as well as the previous prices of the coin and its condition, we could estimate a maximum purchase price around 70-80 euros. Given that the average final auction price has been 52.17 euros and the condition is good, a maximum purchase price around 70-80 euros could be reasonable for this coin in the upcoming auction.