Fry's Electronics was the absolute worst about this. They would sometimes mark items on the shelf down if they were obviously returns, but more often than not

Fry's Electronics was the absolute worst about this. They would sometimes mark items on the shelf down if they were obviously returns, but more often than not they'd re-shrink wrap it and sell it as new. And more often than not whatever it was would be missing relevant important pieces so as to be useless. (This on top of the "we're going to search your bag on the way out of the store", which I would just glare my way out of.) I loved the idea of Fry's having what I wanted, but the actual experience was wretched.