In my neck of the woods, the retailers have the K&N filter at about the same price as a stock filter from the dealer. Last time I checked, the price difference was about two bucks. If I remember correctly, the K&N filter is nothing more than a Hi-Flo product with a nut welded on the bottom. Or so I have been told.
I friend of mine picked up a true Mahle for $13. Three dollars less than the K&N.