I make my own tools and have better luck with them. I bought a set of whale fins that cost $300 and the first time I ever bought any PDR tools and the last.
I have used screw drivers crow bars and just about anything you can think of to fix a dent. not the tool as much as the steady hand and the light. But I never had any schooling on it.
Mine are all homemade too. I made some from deck lid torsion springs. I have a 5/16 inch thick one inch strap that I can bend around using a receiver hitch. Rounded end that I tape a piece of leather to. I get a lot of mileage out of that.