Based on the data provided, we can observe that the coin has had an average auction closing price of 73.16 euros in previous auctions. Additionally, the current condition of the coin is graded at 70 (MBC-).

Considering that the current condition of the coin is relatively good (70), and that the average auction closing price in previous auctions has been 73.16 euros, we could estimate a maximum purchase price around that value or slightly higher.

Given that the starting price in this auction is 30 euros, and taking into account the condition and previous prices, an estimated maximum purchase price for this coin could be around 75-80 euros. It is important to note that the final price will depend on the demand in the auction and the competition from other potential buyers.