Based on the provided data, we can observe that the coin in question had an opening price of 12 euros in this auction, with a grade of 70 (MBC-). Additionally, it has been auctioned in the past on eight occasions, with an average starting price of 54.29 euros and an average closing price of 94.38 euros.

When analyzing the previous prices of this coin, we can see that it has had significant variations in its auction values. For example, in the auction on 2015-04-23, it had an opening price of 200 euros, an estimated price of 350 euros, and closed at 200 euros. In contrast, in the auction on 2022-03-17, it had an opening price of 75 euros, an estimated price of 125 euros, and closed at 110 euros.

Given that the grade of the coin is 70 (MBC-), and considering the previous prices of similar auctions, as well as the current starting price and average closing prices, my estimate for the maximum purchase price of this coin in the current auction would be around 100-120 euros. It is important to note that the final price may vary depending on demand and other factors in the auction.