What Is The Cheapest Frame/Base + Mattress Bed Delivered? (Can Be The Most Basic or Plain Just Needs to Be Functional)

Looking just for a couple of bare bones basic cheap beds to put in a large room.

Any sizes really just the cheapest.

Looking for the frame or base and the mattress for now.

The pillows and even covers can come later.

Doing this to help a charity that wants to quickly fill a large room full of beds for some people in unfortunate circumstances ranging from disaster victims to homeless to people in crisis.

Just hate seeing them sleep on the floor especially on cold rough nights.

So donating some of my money to help out and just help the charity get some cheap beds available asap.

Delivery will be in Sydney.

I have been looking at gumtree and other classified websites for now but extending my options to see what is out there what I can get as a lot of the ads are not fit for humans (soiled/dirty/otherwise).

Just looking for function so can save money on design and aesthetics.