Here’s a photo from Rosen’s book True Mint of his $75k deal for hundreds of low number, black back, 1952 Topps baseball packs.
Rosen wrote that he was at a show in Seattle in 1991 when, right before the show, a man walked in with hundreds of packs of 1952 Topps baseball cards cellophane-wrapped in bricks of six. And since the seller had opened a few, there were also five Pafkos and a bunch of other low-number cards.
The seller told Rosen he got the cards at a garage sale for $50 and didn’t have more, but Rosen wrote that the seller sold several more to other dealers and consigned several low-number boxes in an auction.