Based on the data provided, we can observe that the coin in question had a starting price in this auction of 25 euros, with a grade of 70 (MBC-). Additionally, it has been auctioned five times in the past, with an average starting price of 52.5 euros and an average closing price of 78 euros.

When analyzing the previous prices of this coin, we can see that in the last auction recorded in June 2021, the estimated price was 30 euros and the closing price was 40 euros. However, in previous auctions, estimated prices have ranged between 60 and 100 euros, with closing prices between 80 and 100 euros.

Given that the grade of the coin is 70 (MBC-) and considering the trend of previous prices, as well as the starting price in this auction, we could estimate a maximum purchase price around 60-70 euros. It is important to note that the final price may vary depending on the demand at the auction and other factors that may influence buyers' decisions.