Check with Will Tillery in Danville,VA (right down on the NC line). He quoted my brother $200 for a complete front axle assembly from a disco (same as defender except for the brakes). The rear is also the same axle and should be similarly priced. His website is www.roverguy.com
-he specializes in parting rovers out like Paul Grant in Ct etc.. but is probably the closest dismantler to you. He has a great reputation and I have been very happy with the tranny's, transfer cases, etc. I have bought from him over the years.