Hey mate, fellow Aussie here.
The best starter brush in terms of price and quality for me is the Neo for Iwata. I bought a couple from this eBay seller, excellent price and service: auction
The Neo is a Chinese airbrush built to Iwata specs. It's not as high quality a brush as my Iwata's in terms of engineering, but it's miles ahead of the Chinese knock offs I've picked up over the years. You may be tempted to buy a $20 USD airbrush (the Neo is around USD$50) but you won't even get $20 USD of value out of it. The Neo in terms of quality as an airbrush is superb, it's capable of everything a beginner would want, and even though I've got an Iwata HP airbrush I use my Neo's exclusively now – mostly due to the fact that it doesn't have all the doodads like MAC air flow controllers, it just does what I want out of the box.
In terms of compressors I've got a Sparmax hobby compressor, as well as the one what was being flogged by Aldi earlier this year. Here's a link to the Sparmax on eBay: auction
I'm a bit surprised at the price these go for now, go back the ten years to when I bought it from Hobbyco it was under $200. USD I haven't used my cheap as chips Aldi one (which is a rebadged Chinese model) but I have switched it on to check it works in terms of getting air flow. You should be able to pick up a perfectly fine compressor for less than $200 USD in Australia, but not being in the market for one in a long time I'm not sure which brands or vendors to look at. Definitely do some research though before buying. You'll also need a moisture trap to prevent water coming through the air hose – I used to think that was nonsense till it happened to me at the worst possible time. Moisture traps shouldn't be expensive, here's an eBay link to one: auction
You should also put some thought to paint. The best brands for mini painting is (in order of my preference) Ammo from Mig, AK Interactive and Vallejo Model or Game Air. I no longer waste time trying to dilute vallejo, reaper or citadel paints for use in an airbrush – seriously ignore what some folks say online, these paints can't be used in an airbrush at all. Be wary of Tamiya paints. I like and use them, but they're not acrylic, they're lacquers. Tamiya labelled them acrylic to avoid customs issues for importing into California. Tamiya make excellent paint, but being lacquer they require different thinners and the cleaning process is a wee bit different. Mig, Vallejo and AK Interactive are all acrylics, go with those is my best advice.
You'll need to invest in some airbrush cleaner as well. There are countless opinions about what's the best cleaner etc, but ultimately that's informed by the brush and paints you use. Cheaper brushes, including the Neo, use rubber o-rings to seal connectors and part, which mean many cleaning products and white spirits will corrode the rubber and screw the brush very quickly. Windex is often described as a great all purpose airbrush cleaner and paint thinner, but the formula changes and I've got an el cheapo airbrush disassembled for soaking in a windex mix that I use for my Iwata, but after one night soaking in it all the rubber was melted.
Long post, sorry, but finally also get some Iwata super lube. The Neo will work out of the box when you get it, but giving it a quick service by lubing the needle and the trigger makes a massive difference. Because I bought two Neo's I was able to experiment and prove this. Both brushes worked fine, but the one I lubed up gave a superior spray and the trigger was nice and smooth.
If you go with an el-cheapo, chances are it will have been poorly assembled. With any brush you should always do a full strip down before use for the first time so you're familiar with all the parts, but el-cheapos often have triggers back to front, needles misaligned, even parts outright missing. You don't want to find that out first time you use it!
