I build concrete safe rooms here in Oklahoma tornado country in new homes quite often. We charge about $8,500 for an 8' x 8' x 7' tall safe room with 4000 psi concrete 6" walls and ceiling and rebar at 16" on center vertical and horizontal. The door and hardware costs me about $1,300 but you could probably buy a vault door for a little more money. Some of these vault doors have hardware on the inside so you can still use it as a safe room and get out easily. We install sleeves for an HVAC vent, light bulb and switch, and internet/communication wiring. If you have enough guns to fill one then you have plenty so you need to give some to me.
