Is there no way to get a new one?
If money is an issue, I don't know about other countries but in mine there are plenty of sites, and facebook pages, even city/area-specific where people will give away the stuff they no longer need, or trade or just sell for a low price.
If that kind of thing exists where you live you might find a new bed there? It sounds kinda gross maybe, second-hand mattress.. But you just have to look for a decent one. I recently got one myself for a few euros like that, and there's nothing wrong with it really.
If then transport is still an issue, I'd just ask the person if they could deliver it, and you'll pay for that if they want you to. I've asked this a few times and whenever they can it's usually not an issue.