Hi, sorry to hear about your daughters problem.
I rent out a couple of apartments one of them being a studio like you describe. I supply a sofa bed as part of 'fully furnished' rent. To cut a long story short, you get tenants that treat your furniture well and it lasts - you also get the hooligans that destroy everything at a touch!
Over the years I have experimented with sofa beds. I have bought expensive, cheap, in the middle, 2nd hand etc. etc. the list goes on. it doesnt seem to matter how much you spend, sofa beds dont seem to last if in everyday use. I have spoken with a few suppliers/dealers on the same point that you have and I have had the same answer as you. They claim that a sofa bed is for 'occasional' use and is not designed for every day use.
I find that answer incredible too but, have been told the same.
Sorry if this doesnt cheer you up at all...
