As AliKat said, Paintstiks are one of those things that are much less expensive at art supply stores. Dick Blick has great prices and all the colors of both the regular and iridescent sticks. They also have a video if you're interested. Dick Blick is an exceptional place to do business; you couldn't find better service.
http://www.dickblick.com/products/sh...s/#description and
http://www.dickblick.com/products/sh...ik-oil-colors/
A word of caution if you are thinking about getting the student grade to save some money; they are cheaper because they have less pigment, and less pigment makes for less intense color.