And btw, when a canadian retailer was selling a kit like OP request, it was 1225$. Contained everything except a lower and an upper, so you'd still have to add an upper, running an extra 100+$.
Still think it's gonna be cheap to build your own?
To be fair you could build a completion kit for less, but no way you could build one for less than the price of the PSA I posted earlier. Even PSA's pistol completion kits are almost as expensive as whole rifles, and they look really cheap.