Check out this advertisement from Kit Young from the September 1991 issue of Baseball Cards magazine.
At the time, a complete case of 1989 Upper Deck High Number Factory Sets was $1,495, and a 1952 Topps Willie Mays card in Vg-Ex condition was $575.
For context, REA sold this PSA 4 graded 1952 Topps #261 Willie Mays card for $8700 in December 2023.
And those 1989 Upper Deck High Number Factory Set cases? Well, Steel City Collectibles sold one on eBay for $659 in January 2024.