Just google "motorcycletires" there hundreds of discount providers...but I would beware of buying tires online...look for them locally if possible.I have ordered before and they had sidewall cracks..pain in the butt to return .bought locally.Savings not worth it.
Try American Motorcycle Tire. You can't beat their pricing and the service is outstanding. I know I sound like a salesman for them, but I've bought numerous tires and support equipment from them and they can't be beat.
Americanmototire again. Been ordering from them for years. Only problem is its hard to talk to a real person. They awnser email next day if not the same day.