Based on the data provided, we can observe that the coin in question has had an average auction closing price of 263.93 euros in previous auctions. Additionally, the condition of this coin has been described as '85 (ebc-)'.

Considering that the condition is quite good (85), and that the average closing price has been 263.93 euros, we can estimate a maximum purchase price around 300-320 euros for this coin in the upcoming auction. Given that the starting price is 400 euros, it is likely that the closing price will be below this value, but it is important to note that the final price may vary depending on the demand at the auction and other factors that may influence the bidding.