I haven't been keeping track of the rearend build cost, but I dont' have much in materials. However, the time spent is pretty high. If I had to sell them, I don't think I could sell it any cheaper than TRZ. I would have had them put their brackets on my housing, but they don't modifiy other peoples housings anymore. And I simply cannot afford one of their fabricated housings. This has been fun though. Fabrication is my other hobby, so the time spent is enjoyable.