Check
http://www.car-part.com as this is a quick way of getting used parts, even delivered!!!
Also, check your local salvage yards. Next, national auto parts stores, internet cv stores, etc.
Just beware, that most stores sell a used refurbished axle. At times, this is worth the cost difference, other times, likely you'll need, is a total new. Rebuilt is the CV itself. It must pass certain criteria for rebuilding. Most of the time, tolerances on not met, but they still rebuild.
Good luck.