Seriously though, all the answers you got are from knowledgeable people. The only way any of us could give you a good answer would be to look under your hood........

ohmy: No, not what you're thinking.........the VAN's hood!) and look at the components in question.
The trouble is, replacing the tension pulley isn't rocket science, though the shop will try to convince you that it is. Usually one little bolt is all that holds it. They'll charge you something like two hours labor for a half-hour job. I replace em myself and pocket the money for a couple of cold beers at a later date.