The place to buy bearings is

AVID RC BEARINGS

They have tons of options, whether you want rubber, metal, teflon, half rubber/half metal, and in lots of sizes.
I ordered 11 bearings from them, costing me 13 dollars. EACH BEARING IS ONLY $1. They are good quality too. The shipping is a flat $2.00 and they get new varieties almost every week. I highly recommend them. Oh and they also packaged them nicely.