Where I live in Central NJ, 2 chain hardware stores plus a plumbing and heating store in town. My last foray into plumbing, the water flow wouldn't stop in the toilet, realized the tab that presses down on the valve had broken off. Bought an adjustable unit, it couldn't take the water pressure,bought a fixed length. I note on the original the tab was just a molding, on the replacement unit, it was a brass screw, allowed for finer adjustments. And yes, I DID turn the water off before I started.
Another rule for plumbing repairs, home repairs in general-NO audiences !
The friend whose mishap I mentioned above said it's amazing how, when a toilet needs repair everyone loses control of their bladders and bowels. My friend said the next day he came with the replacement parts, he told his wife, kids and MIL OUT !!! And I don't want to see you back here for THREE hours !