So much for the “business deals in parking lots” market.
No answer to the biggest question — why on earth would you do this on a blockchain in the first place?
You can say “crypto” all you like — but if you’re dealing in actual money, you have to work to the rules of actual money.
What is bitcoin, anyway? A miserable little pile of nonces.
And the cheapest way to get a good video card now? Buy a high-end pre-built PC and rip it out.