I have a med priced one with removable covers, unfortunatly not machine washable, not that they would fit in anyway. But it has lasted well, getting on a bit now, FIL had to add a support under the middel as it is about 7ft long so was sagging in the middle.
All in all happy with it.
My bed is a bed settee from Ikea too, design for everyday use, neve folded into a sette always just a bed, had it for about 5 yrs, I am starting to feel the slats through it now and changing it for a proper bed.