In my opinion, it's people prospecting rookies and grading them, hoping for a gem mint PSA 10. Let's just take Juan Soto for example. Nice, young ballplayer with his whole career ahead of him. He's "on the right path" for possible enshrinement for the Hall of Fame. His rookie card was in 2018. He was arguably the 4th best rookie that year in terms of baseball card value. Acuna Jr, Ohtani, and Torres being the other 3 big ones. A Soto BASE Topps Update rookie card sold today on ebay for $60.00. A Graded PSA 10 of the same card sold today for $232.50 A Soto 2018 Topps Chrome Update (Target Exclusive) UNGRADED card sold for $170 on ebay. That's a nice investment for a $20 box of cards. A GRADED PSA 10 of the same card has sold on ebay for $687.80. That's huge. That's just Soto for example. There are plenty of others. Everyone is prospecting for the next Trout....whose PSA 10 2011 Topps Update card just sold for $4000.......... Not to mention Target, Meijer, Walgreens, Walmart, etc have special color variations (Yellow, Red, Blue, etc) of each of the base set cards in Topps. These colored variations of these rookies go for a premium. For example, a 2019 Topps Update Hiura Walgreens Yellow Border just sold for $35. His normal base card for 2019 Topps Update sells for a few bucks. My best advice if your looking to get some cards for your kids would be to go to an actual card shop or online. I used to recommend any Topps Jumbo box as you most often get a complete set. They used to cost $100-$150 2-3+ years ago, but now cost in excess of $250.....it's just crazy.