I picked up one of the $20 ones from orcheln's this summer. For the price it's awesome, it cuts well and self cleans well enough I only have to clean out the fine side when rasping soft stuff like eastern red cedar. I've never used one of the high dollar ferrier rasps, but if they cut significantly better Id be surprised. After having one for a while now, I don't know how I made bows without one, especially from knotty character staves.
Kyle