if you spent all the money for an NFA M16 lower what's another $40?
for semi-auto safe queen internet centerfold AR's it's just another part to brag about having... like the D-fender, crane o-rings, HK style sights, all chrome bolt and bolt carrier, enidine buffer, etc...
it could be worse... you could be wasting your money on airsoft SOPMOD stocks and chinese aimpoint knockoffs...