Cheap Jack
Cheap Jack is slang for a peddler of cheap goods. Cheap jacks are the guy selling flip flops at the beach, or the girl selling sunglasses at the fair (maybe they should be called "Cheap Jills").
Originally, this direct-to-consumer sales term more specifically referred to traveling salespeople or people at local markets. But since we've pretty much eliminated traveling salespeople (except for religion and politics), the term has since expanded to include all cheapo peddlers. But don't worry if you find them annoying. Eventually, they'll all be replaced by Amazon kiosks.