Just realized those windowed boxes that comes with 1/18 diecast like Autoart, Novel, Hot Wheels cars actually make pretty decent framed display case, you can even keep the frames intact in the box and for those that collect diecast cars this is a space saver means of reusing the boxes (provided they aren't dented). The box height is slightly taller than average 1/6 dolls and they usually have windows on all sides except the back and bottom of the box so lights can enter and doll can be seen clearly on 3 sides. Best part is the box cost nothing and you don't need to figure out where to store all these boxes.

But of course higher end cars do not come with windowed box so there's that. Just remember to hold the box from the bottom when moving it around, don't want the doll to slip out from the bottom.