Re: Bunk Mattresses
I guess it depends on what type of firmness you need. We use thick, good outdoor patio furniture cusions (7' long). Usually find them on clearance end of season for $10 bucks each. One in the family has to use two of them for comfort, he likes his beds soft soft soft. Rest of us are tough buggers, don't need that much fluff.
I have heard that fabric stores carry foam, not sure how good it would be though.