Most (if not all) courses @ Udemy appear to be A$19 until 10/10/2017 which makes some courses discounted up to %90. I had to be logged in to see the discounted prices so it might be targeted. There was a purple banner across the top.
Like many fellow Ozbargainers I'm enrolled into hundreds of courses of which I only completed 1.5 (hey I probably still rank at top 1%). Thanks to Ozbargain I never paid a cent to Udemy so they are definitely not rewarding me for doing business with them :)
I was looking into purchasing some REST API courses as there were no free ones posted. A significant investment I know… I could have bought 1900 plastic egg yolk separators for $19!