Tirerack and Discount tire have good selections, but after searching and calling both, I found that the only lightweightwheels at the Rack are $230+ each. Discount Tire has only heavyweights - at least only stuff that's heavier than 14 lbs or so.
You really have to look elsewhere to get lightweight wheels, since the last thing you should do is buy wheels that are heavier than the factory ones. Your ride and acceleration will suffer.
So take a look at this place for some lightweight Rotas that don't cost aywhere near $200 each. Many are available in Royal colors (polished lip).
http://www.jaydm.com/wheels.htm