This video kind of got buried in another thread but I thought it worthy of its own discussion:
https://www.youtube.com/watch?v=rvLFEh7V18A
This is a nearly 1-hr, well-documented expose of price manipulation and deception in the video game market by game grader WATA Games, the top grader of video games, in partnership with Heritage Auctions. It extensively details the shady background behind Jim Halperin (including settling price manipulation charges and lying about the existence of a group he was part of) and the seemingly-fraudulent interactions behind WATA and Heritage. This includes WATA directors grading their own games, in violation of WATA's supposed policies and then selling them through Heritage. It details Heritage proclaiming that they would sell WATA video games - before WATA had even opened up shop. And on and on and on.
The implications are pretty obvious for other areas like sports cards.
I recommend you take an hour of your time and watch the video.