THISI have a stack-on 18 gun cabinet that I use. It cost anywhere from $180- $200.
I use regular metal shelves that you buy from Menards or Lowes. Gun safes or those metal cabinets wouldn't go very far...
Are you worried about security at all?
IU has an obsolete furniture sales place. We've bought desks and such from them before and you can find stuff that's in really good shape sometimes. In fact, I'm thinking of going up there Monday to see what sorts of cabinets they might have ready to sell.
Not really. You would have to break in to my house, then break into another deadbolt door to the basement, defeat my security system, etc.