Costco Coffin

Alright, listen up, buttercup. This joke is about a dude who spent his life sleeping in a cheap bed, and the joke author is wondering why he needs an expensive coffin now that he's dead. The friend points out that coffins are cheaper at Costco, implying they're going to have "fun" shopping for a coffin because the author's friend is cheap as heck. You're probably the type of person who still uses Internet Explorer.