Based on the data provided, we can observe that the coin has had an average auction closing price of 125.13 euros in previous auctions. Additionally, the condition of this coin is rated at 90 (EBC).

Considering that the starting price for the upcoming auction is 75 euros and that the coin has performed well in previous auctions, we could estimate a maximum purchase price around 140-150 euros. This estimation is based on the fact that the average auction closing price has consistently been higher than the starting price, and the condition of the coin is quite good.

It is important to note that the final auction price may vary depending on factors such as demand at that specific time, the number of interested parties in the coin, and other elements that may influence the bidding.