Based on the data provided, we can observe that the coin has had an average auction closing price of 68.08 euros in previous auctions. Additionally, the current condition of the coin is 90 (EBC), indicating that it is in quite good condition.

Considering that the average auction closing price has been 68.08 euros and the coin's high condition, we could estimate a maximum purchase price around 75-80 euros. Since the coin will be auctioned in the coming days, the closing price may be slightly higher than this range, but based on historical data, this would be a reasonable estimate.