Based on the provided data, we can observe that the coin in question has had an average auction closing price of 72.89 euros in previous auctions. Additionally, its current condition is 75 (MBC).

Considering that the starting price in the upcoming auction is 30 euros and the historical average starting price is 37.88 euros, we can assume that the closing price could be around that range.

Given that the coin is in good condition (75 MBC) and has performed well in previous auctions, we could estimate a maximum purchase price around 70-80 euros.

It is important to note that the final auction price will depend on various factors, such as demand at that specific time, the number of interested parties, and participants' willingness to bid beyond the estimated prices.