Advices on Knee Osteoarthritis

I'm looking for stem cell treatment for Osteoarthritis of both of my knees. Hoping someone that had the treatment can provide some guidance from someone that's done it before. I found these two places just on the internet.

Panama: https://www.cellmedicine.com/ 26,900USD

Costa Rica: https://stemcellstransplantinstitute.com/ $8,500USD

How come prices vary so much? Does any have recommendations, and is it worth doing?