the unfortunate thin about fitting is that, once you're in a session with the fitter, it's hard to back out. I've had two professional fittings, both at bike shops with a good reputation.
the first one was old school and didn't use cameras or anything like that. he took my rowdy hardtail and put a slammed 100mm stem on it, then slid my cleats all the way forward under my toes so that he could force my knees into a KOPS position. I paid my $100 for that fitting feeling good about it because of his confidence, rode the bike one like that and I was in so much pain that I had to stop mid-ride to put my cleats back in a rational place. I kept his advice to lower my handlebar but the long stem put me in a bent-over aero road bike position that made no sense at all. in the end, it was a total waste of my money. I should have just walked out without paying the second he pulled out the plumb bob to force my knees into KOPS instead of adjusting the eccentric bottom bracket on that bike or move the saddle forward.
the second fitting used a very advanced video motion capture system. Guru maybe? because he knew what he was doing and had tools to get some precision, the fit came out much better. I did that over three years ago and I still use that fitting as a starting point.
Look up "Bike Fit Advisor" on YouTube. that guy seems to know what's up.