I was in the market for new rotors and ended up getting a set for pretty cheap. Front and rear was $105, just fronts is $65. This was for a silver coating (prevents rust), and no cross-drills or slots (although they can do this for extra).
The company is Inet, and other members here have them, and have had good things to say. i figured I'd give you the heads up as it is a great deal for good rotors that won't rust. If you go to Ebay, type "rotorize" into the search engine. They don't specifically list the IS300 on ebay, but I called and they are shipping mine next week.