@Roger 's budget for the original Sawppy was US$500. That's about AU$750 right at the moment.
Given that I'm going to be paying a lot of postage, if we get in under AU$1000 I think that will be OK.
The need for postage comes from living on the western edge of Australia - a long way from anywhere.
I made a reasonably determined effort to try to get the parts required from local (Western Australian) suppliers, but I gave up the fight before too long. Another long story short: Too costly. Too limited. Just too hard.
Even online ordering from Australian businesses on the east coast yielded roughly the same story. Ebay same. Amazon same.
So... Hello, AliExpress! Everything you could possibly want, you just have to wait for it to arrive.
Exhibit #1: Aluminium extrusions - Just couldn't get the right profile let alone the right dimensions in WA. About $4 per metre length from AliExpress (I got black anodised). AU$30 delivery for 5 x one metre lengths. Took just a week to get here.
Exhibit #2: The servo motors. I'm sticking with Roger's recommendation on these because I don't know enough to argue. Found the right ones on Amazon US - AU$22 or something, plus shipping. BUT you can't buy third party items from Amazon US and ship to Oz. Got referred to Amazon Australia - same servo motors are now AU$25 plus shipping. And they only have four (I need ten). AliExpress? Some RC shop has a thousand on the shelf. AU$22 including shipping and you get a free debug board.
So I sat down one night a couple of weeks back and ordered about AU$400 worth of parts on AliExpress. It's starting to arrive now :)