I have used mostly discount stores like Marshall’s, TJMaxx, Ross, and Play it Again Sports. Dumbbells I usually buy new so they aren’t rusty or torn up but Play It Again Sports is cheaper than other Sporting Good’s Stores. I paid full prices for a step and risers for safety reasons. Of the few years I have been in business, my clients have given me equipment that they purchased but never used and any time I see something, like a medicine ball, I grab it up. My massage therapist used to be a PT and she gave me stuff. Networking and letting folks know what you need and it appears.