Some places give away wooden pallets for free. You could utilize those - even double stack them for more height.
Speaking from experiance, when it comes to new babies, young children & house guests - the bed isn't as important as a nice, over stuffed chair, one that rocks is priceless and a TV in the room.
Hondo Von Dopplet L Bauernhof "Hondo"- GSD
Lilie's Tug McGraw "Tug" - Golden Retriever
Maggie - Mini Dachshund (Rescue)
Lonestar Pivo - Texas Blue Lacy
Ashe - Barn Cat
Katie / APHA