The new Behr units list for $236 - BMA has them for $200. You are much better off with a Behr unit. I have no idea who Autozone is using for a supplier on those parts - I would hazard a guess that they won't last very long or run as quiet as the origina Behr stuff. The motor on my e28 535i was a $350 unit !! The bronze bushings went bad in it and I manged to repair it using some R/'C car ball bearings.
The only thing I buy from Autozone is oil and checmicals.