Do note that the B-Stock items at Swee Lee are now indicated online. These are perfectly functional instruments with cosmetic blemishes. They are also subject to the usual warranty covering standard items. As seen here, prices are also slightly discounted.
This practice isn't special by any means but the stores here are not observing it as a standard process to see off products which are subjected to acceptable wear & tear due to handling (display items subject to customers' trying, chemical reaction due to temperature changes, etc.). This is usual practice for major US stores because they know better than letting such items rot at the shelves & affecting sales.