$850 is too much. Several recent Ebay completed auctions in the $499-$599 range. One Buy It Now went at $699, but $850 is too much of a premium for the card.
Concentrating on my personal collection. Please drop me a PM if you have any of the following for sale: Topps Football 1959; 1961-1964, 1967; Philadelphia Football 1964-1967, Topps Baseball 1957-1968