I think John is spot-on with his recommendation. The OEM cooler is fine and a substitute for your planned use is not needed.
Will there be a price cut on Athlon's coming up - you can count on it! That's the nature of the beast in this business. 6 months from now a whole new crop of motherboards, video cards, and cpu's will be in place with a whole lot more on the drawing board for introduction in another 6 months etc. etc etc and this is being conservative!