Check out www.mscdirect.com. They sell aluminum extrusions with various tooth configurations to fit standard toothed belts. Simply slice off a piece and you have a toothed pulley.
You might also want to check into the pulleys on junk overhead cam engines, notibly Subaru. They have twin overhead cams and therefore a couple high quality toothed pulleys on each engine. You might be able to find low cost pulleys there.