Changing a rear axle shaft is not hard. Neither is changing the bearings. Price out and locate a replacement axle shaft from your local salvage yard or use car-part.com. This will give you an idea of the part availably and price.
Perform the tear down in your drive way. Then you will know if it needs a new shaft. Replace the bearings and go from there.
Perform the tear down in your drive way. Then you will know if it needs a new shaft. Replace the bearings and go from there.