I agree with the "buy used" sentiment. I have a super-single that our
son has not had room to take. A dealer told me that it was worth $50
tops. He chopped his up to get rid of the thing. The conventional beds
with water-tubes in a soft-side mattress are popular.
The construction is very chintzy - drawers without slides, soft pine
1x2 and masonite drawer bottoms. All covered with a dark stain to make
it look attractive. Joints are only stapled together lightly. Little
glue, no screws.
I have a king size with captain's pedestal: 4 drawers and two doors on
each side, one door at the foot into a tunnel up the middle. Simple
3/8" plywood deck boards.
The super single, queen and king can all use the same pedestal and side
rails. The only difference is the width of the footboard, dummyboard
under the head and whatever headboard sits on top of the rails. So, you
can actually use ANY size and stretch it to fit.