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 and is in a conservation grade of 70 (MBC-). Additionally, it has been auctioned in the past on several occasions, with closing prices ranging between 20 and 160 euros.

The average closing price of this coin in previous auctions has been 73.03 euros, with an average starting price of 45.59 euros. The conservation grade of the coin in previous auctions has varied between 30 and 95.

Given that the coin is in a conservation grade of 70 (MBC-) and considering the previous closing prices as well as the average closing price, we could estimate a maximum purchase price of around 90 euros for this coin in the current auction. It is important to note that this is just an estimate and the final price could vary depending on the demand at the auction.