Based on the data provided, we can observe that the coin has had an average auction price of 74.39 euros in the past. Additionally, the condition of the coin in this auction is 75 (MBC).

Considering that the condition of the coin is 75 (MBC) and the historical average auction price is 74.39 euros, we could estimate a maximum purchase price around that value. However, keep in mind that the starting price in this auction is 12 euros, so the final auction price may end up being higher.

Therefore, my estimation for the maximum purchase price for this coin in the current auction would be around 75-80 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 the bidding.