Vacuums can be pricey, sure, but do you really want to buy a used one that might not be in working order? Vacuum cleaners get banged around, dragged up and down staircases, and the fact that someone chose to get rid of the vacuum should be a red flag—most likely, there was something wrong with it. Plus, vacuums have seen their share of dust and grime from someone else’s home. Chances are you don’t want to bring that into yours. These are the secrets thrift store owners aren’t telling you.