Based on the data provided, we can observe that the coin in question has had an average auction closing price of 65.57 euros in previous auctions. Additionally, its current condition is estimated at 80 (MBC+).

Taking into account the previous prices of this coin and its condition, as well as the fact that it has been auctioned 8 times in the past, we can estimate a maximum purchase price for this coin in the upcoming auction.

Given that the average auction closing price has been 65.57 euros and the current condition is 80 (MBC+), we could consider an estimated maximum purchase price around 70-75 euros. However, please note that this is just an estimate and the final price may vary depending on the demand at the auction and other factors.