Custom 16" 1x9 5.56 Chrome Moly Carbine Upper NO Bolt/Carrier or Charging Handle
fairly inexpensive m4 upper. no bolt or charging handle.
not quite as mall ninja-ish as the DSA for $275 but should make a decent m4-forgerie for little $$
probably run like a clock with the LMT bolt carrier or other bcg and a cheap $15 charging handle.