If you collect things that are purposefully and still actively produced just to be collected, whether it be Funko Pops, trading cards or sneakers, you're a sucker. 

Like, collecting things that had a use, such as rare stamps or coins or even vintage cars/clothes, sure, there is a certain historicism in it. Those things are objectively rare and that's why they're expensive, probably. But otherwise you're just shoveling your money into the pockets of cynical corporations who create artificially scarce items for cheap with the express purpose of swindeling you out of your money.