Based on the data provided, we can observe that the coin in question has had an average auction closing price of 140.62 euros in previous auctions. Additionally, the condition of this coin has been described as '70 (MBC-)'.

Considering that the condition is '70 (MBC-)' and the average closing price has been 140.62 euros, we can estimate a maximum purchase price for this coin to be around 150-160 euros. Given that the condition is not the highest and the average closing price has been relatively stable in previous auctions, this estimation seems reasonable.

Therefore, my recommendation would be to consider a maximum purchase price of around 150-160 euros for this coin in the next auction.