My GC liked their ready beds but of course have now outgrown them. However, I think I saw something similar advertised for adults, so perhaps they would have them now for bigger children.
Ikea do a trickle bed that slides under a single bed and then can be raised to bed height - we use ours un - raised for rubies and raised for bigger people!
My daughter is giving her niece and nephew (4&6) a complete blow up bed for Christmas. They are complete with pump and sleeping bag type covers. I think they came from Costco.
Have you thought of a travel cot? Most of them can be used up to 3 years old and pack away very neatly for storage (my GS's travel cot goes under the spare bed)
Please can any one recommend a small fold up bed for toddlers. I prefer something light weight that I can store in my garage and carry easily up stairs. If not have you any good improvisation ideas? Thanks