Based on the data provided, we can observe that the coin in question has had a starting price in the current auction of 18 euros, with a conservation grade of 75 (MBC). Additionally, it has been auctioned in the past on several occasions, with closing prices ranging between 18 and 420 euros.

The average starting price of previous auctions has been 52.63 euros, while the average closing price has been 78.13 euros. The coin has been sold in 88.89% of previous auctions.

Considering the previous prices of the coin and its current conservation, as well as the fact that it has sold in the majority of previous auctions, we could estimate a maximum purchase price around 60-70 euros. It is important to note that this is just an estimate and the final price could vary depending on demand in the current auction.