If you are looking for a cheap twin mattress for your guest room or for your children room, you have a lot of options to consider. Your best bet is to go with innerspring mattress, because it won’t have to take much weight at all. Children are simply not heavy enough to sagg the bed while guests will stay only for a short time, so the bed would endure for quite a while and you will save money. And since many companies make good innerspring models, you will easily find a cheap twin mattress for your room. I suggest you go with Serta or Spring Air if your children will sleep on it. If guests will be the only one using the bed, you can go with even more affordable brand like restonic or Englander.