Yes, so much so that cards that were sold at retail in 2024 after grading sold went from around $100 in cost to well over $1000 in 18 months, and this was me making the market. The prices have since 2.5x-ed on the same card (2024 Topps Chrome Sapphire Base #500 PSA 10). It's correcting a little, but a 10x rise on a card that is effectively not considered limited edition and most had placed in storage suddenly 10x and then 2.5x is quite rare, especially since it's a new card.
These are just public sales. Private deals are done with agents on both sides routinely and without any reportage. There's an element of gambling to most transactions but on the origination side, mostly because Topps, who owns licenses to the major sports leagues, are neither timely nor accurate in posting pack configuration odds, and seems to somehow have nobody competent enough to properly ensure that the same cards don't all get clustered in the same box. On multiple occasions I've bought cases where 3 out of 10 cards of a player were pulled, and multiple 2/10s. The checklist is only 100 cards. The case had 384 cards total. It's downright negligent, but screw the consumers, right? Thanks, Lina Khan, for making it all happen.
There's money to be made but it's a lot of dumb money mixed in with some very sharp acquisitions. Who knows how it'll play out. The market is inefficient largely because USPS is effectively a crapshoot in a time-sensitive market. The likes of Courtyard.io have only partially caught on, and ArenaClub, their competitor, ran for 2 years where a bookmarkelet allowed the user to turn what was supposed to be a random draw into a completely predictable purchase at way below market. Upon reporting, they just added a line in their ToS that put users in theory on notice. They did not fix the bug. They don't even have a SECURITY.md. The company served so much unnecessary data on their API that I now have Steve Nash's personal cell number, among others, before they designed their front page.
There's a gold rush going on but this really should be a hedge. At some point the market correction will screw over a ton of people.