Based on the data provided, we can observe that the coin in question has had an average auction closing price of 413.48 euros in previous auctions. Additionally, its current condition is estimated at 70 (VF-).

Considering that the coin's condition is relatively good and the average auction closing price in previous auctions has been 413.48 euros, we could estimate a maximum purchase price around 450-500 euros. Since the coin will be auctioned in the coming days, the closing price may be higher due to demand and competition among bidders.

Therefore, an estimated maximum purchase price for this coin in the upcoming auction could be around 500 euros. It is important to note that this is just an estimate and the final price could vary depending on various factors in the auction.