I would imagine the NIL boosters are going to start putting clauses into the contracts to stem some of this madness.
Could a booster at, say Auburn, write clauses into an NIL deal that says something to the effect of "we will pay you 2 million per year to sponsor Bubba's Used Cars, so long as you are a member of the Auburn football team. Leaving the Auburn football team is a breach of this contract. Any party who breaches this contract is liable for 4 million dollars in liquidated damages."
Now, if the kid is Cam Newton and wants to transfer to Bama, some Bama booster will pay that damages clause for him. But there's gotta be some limit.