Willie Mays' 1951 Bowman baseball card. The last time a mint one sold, in 2008, it fetched $86,000...
The survey was just released by PWCC, the largest seller of investment-grade trading cards ($60 million in annual revenue). Results are generated using an index the company created in early 2018 based primarily on the sale prices of the 500 and 100 most valuable trading cards...
The index excludes the $3.12 million ca. 1910 "Jumbo" Honus Wagner and the mint $2.88 million 1952 Topps Mantle because their extreme scarcity makes them outliers.