I have one of these in the nightstand with the drawer-front modified to swing down instead of pull out (although you still *can* pull it out)
Fort Knox PB4 Personal Pistol Safe
appears to be currently unavailable, but I paid $215-ish the last time (2015)
and one under the passenger seat in our campervan.
V-Line Slide-Away Security Safe, Semi-Flat Black
about $370 now, which is about $100 more than I paid.
Been thinking about one of these for under the desk
V-Line 2597-S Desk Mate Keyless Security Box with Quick Release Mounting Bracket (Black)
Quite happy with them in both applications, and haven't had any fitment issues. Pic below from the Fort Knox listing above shows two dummy M92s in one, to give you an idea of size.