Stuff Etc. is a consignment store by and large, which made this odd. Definitely wasn't someone brought a few pieces they couldn't sell in, this was cases of overstock.
ETA: Actually I'm pretty sure I know where these came from. There was a toy shop here last summer that came and went in a flash. I remember they had some of these assortments in stock at the time. I bet they gave up the remainder to consignment.