A smaller S/C pulley at autozone? LOL.
GMP will probably overcharge for a pulley like with everything else they sell. There is a vendor on here already selling pulleys for Cobalts, South Florida Pulley Headquarters, or S.F.P.H. I believe is his s/n on here. Talk to him if youre interested in upping your boost. Remember though, its a good idea to do a few supporting mods before you do a pulley swap, like a new intake, exhaust, colder plugs, and a 180* thermostat wouldnt hurt either.