I think it’s a very exciting area of research, and early trials (which do NOT charge participants) have been promising. However, it’s still early stage research, and there’s no way I’d pay anyone to experiment on me!
The clinical team here in Bristol have been involved in some (so far) very small-scale trials, with some success, and I believe another is either recruiting or underway at the moment. They certainly don’t charge a fee, and it would be unethical for them to do so.
At least one commercial clinic was found not even to be offering human stem-cells (preferably the patient’s own), but ones extracted from cows! No evidence whatsoever that it worked, plus it was potentially dangerous (think of how BSE was transmitted), but patients were charged £10,500 a time.
The doctor was struck off for offering patients: “pointless and unjustifiable treatments” and causing them “lasting harm”.
Desperation is never a good reason to part with your money.
You could consider registering to see if you are eligible for any forthcoming trials, though I don’t know much about it I’m afraid - even though one of them is local. You’d have to ask your neuro how you express an interest.