I got my Stag kit a few years ago from AR15Sales.com
They have a few other brands, and I really liked that they didn't spike their prices around the last election. I clicked "buy" the night Obummer was elected, and the kit (rifle minus stripped lower) was only $625 ish.
i was asking because someone told me they couldnt find any kits for under $500. i remembered JSE had them for like $430, but couldnt remember the site.