Based on the data provided, we can observe that the coin in question has had an average starting price of 51.11 euros in previous auctions, with an average closing price of 70.14 euros. The conservation status of the coin has been described as 70 (MBC-), indicating a fairly acceptable condition.

Furthermore, several auctions have been conducted in the past, with varying starting and estimated prices. In the last recorded auction, the coin had a starting price of 15 euros and an estimated price of 25 euros, but the closing price was not recorded.

Taking into account these data and the history of previous prices, as well as the conservation status of the coin, we could estimate a maximum purchase price around 80-90 euros. Given that the average closing price has been 70.14 euros and the conservation is good, a maximum purchase price in that range could be reasonable. However, keep in mind that the final price in an auction can vary depending on demand and other market factors at the time of the auction.