Cheap?
Depends on your definition of cheap... Check your local parts stores and you *MIGHT* be able to pick one up for $100 or so. I've never really priced them other than doing a quick search... Jegs has them for over $300 for a good one...
Be careful about going "cheap" though... Even if you pick up a used one from a salvage yard, you'll still need to spend the $40 or so to have it machined. If you buy it online from somewhere, you may be hit with a pretty stiff shipping charge...
You'll have to shop around... CJs has them for $230 ...
http://www.parts123.com/PartFrame.as...=CJ_Pony_Parts but I'm sure you can find it cheaper at an Advanced Auto Parts or Autozone...