Probably worth digging up that old thread. IIRC, he added the fab furniture to the gun gave it his killer (sarc) foliage and red paint job w/ eagle stencil and had the gun listed on his website at $750 or $800 or something crazy. So ~$300 for his stock and furniture and rattlecan job... Might have been on armslist too at the time as well as his website...
Bottom line, a cordless drill is not an impact driver. And a breaker bar, ratchet, or even a large handle screw driver would have given him more torque... And no mention of the needless removal of the stock arm.
Regardless, his videos are a hoot, and I hope his apparent tacticool gunsmithing and training venture fixes more than it breaks...