I use an IKEA book shelf. Its the type that you can buy glass doors as an extra. For the price of one tamiya kit, PE and fruils, I say its well worth it. Looks nice, keeps models safe and clean and hold a lot of stuff. I used to make my dios all on a standard frame size and filled up the dio to suit. Now I try to build tighter, more compact dios and try to increase the detail and then buy a frame to suit. Takes longer and is a better finished product.
Of all the places in your bedroom that dust collects in, is undery our bed the worst! This is the last place i would store them. If they get dusty, they may be hard to clean. Id rather buy boxes and build them in the garage or basement!