From what I've read here most users don't recommend UK clinics or surgeons since they overcharge and aren't worth the price for what they offer. And PRP is mostly seen as something extra that could be somewhat useful if done by an expert who delivers good results and with the proper technique and equipment, but not something to rely on, since there aren't many conclusive studies or techniques that guarantee regrowth or thickening. Some guys say it could be worth it after a transplant. Generally you want to avoid PRP unless you've got plenty of money to spare since it doesn't give great results for how costly it is. Greedy clinics and doctors try to push it to you because it's very profitable. You're better off sticking to the big 3 and using the money to buy a dermapen, tretinoin and/or something else, at least at first.