I've always said I'd never buy a used mattress. How can you know it's been cleaned and sanitized?
Discussion
There's nothing wrong with buying new. But most of us are reasonably comfortable sleeping on hotel mattresses which may have been previously used by hundreds of people whereas a used mattress typically was used by one or two people.
Also nice mattresses typically come from nice homes.
Great point, I've slept in too many hotel mattresses to count!