Based on the data provided, we can observe that the coin has had an average auction price of 186.77 euros in the past. Additionally, the current condition of the coin is 85 (ebc-).

Considering that the coin will be auctioned in the coming days with a starting price of 80 euros and has had an average starting price of 97.92 euros, we can estimate that the final auction price could be around that range.

Given that the condition of the coin is quite good (85 ebc-) and considering the previous price history, we could estimate an auction price for this coin in the range of 180 to 220 euros.

Therefore, my estimate for the maximum purchase price for this coin in the upcoming auction would be around 220 euros.