If you can swing it,,in shotgun news(i always buy one of these when im building an AR)there is a ad for complete kits,everything but a stripped lower,,,you can get 3 flat top w/detachable handle kits for 1,149,,get yourself 3 cheap stripped lowers as low as 65 bucks each.
You can pretty much sell 2 and the one you keep,,ya might have NOTHING or at the most 1-200 dollars in......X