I've had a german shepherd pup for the last 3 weeks, her breeder mentioned no stairs for at least 4months, so we're carrying her up and down, ours stairs are inside though and the only time she really needs to go up stairs is at bed time, so its only a once a day thing. I was considering basket or something for when she gets bigger and is more awkward to carry.
Cheapest thing with hard floors, carpet offcuts, we're in a rental for the next 6-12months, and downstairs is all tiled and up stairs is polished wood, for less then the price of one big rug, I've been able to cover practically all over the floor downstairs and I the bonus is we don't have to stress out about rugs having accidents on them or the end being ripped, we're still teaching her not to but its not like its $180+ rugs getting wrecked.
Not sure where in NSW you are but if your in Western Sydney shoot me a pm I'll give you a number/link for where I got our offcuts, it came up when I was looking for the cheapest rugs possible lol