There is enough profit to pay people to buy stuff and resell it.
I've watched vans dropping of an endless stream of people in the parking lot of my local Costco to buy out all the cases of Pokemon cards within 20 minutes of the "random" drop they put on the floor. They go in, buy the max quantity of the item with cash provided by their keeper, bring it back to the van with a receipt and change, and get the $20-30 per item pay they were promised. There were 2 or 3 'legit' buyers out of hundreds of obvious straw buyers.
If the profit per item is $4-5k, expect this to go into turbo mode and be done in a marketplace/automated fashion and go viral. Just sign up to your favorite scalper's platform, submit your information, get a quote and a prepaid label and drop the box you got from nVidia off at USPS the next day. That "tens of thousands" of individuals will turn into "millions" really quick once it gets known there is rent money involved by clicking a few buttons and it goes viral on all the social media platforms.
The only way out from that is manufacturer enough cards to meet demand, and at that point the retail channel doesn't really matter.