Following on my Argentinian value selections, here are my five best wineries for inexpensive wines (below C$20) from Australia. These are not in order of preference although the Yalumba/D'Arenberg selections are the preferred. Note that these wines are widely available on restaurant menus, so are worth knowing.
D'Arenberg: While famous for some pricey offerings, D'Arenberg has a way of being amongst the best wines at every price point. The whites are great deals, the "D'Arry's Original" is a great value, and "The Footbolt" Shiraz is close to being the best value on the planet. Consistent year after year.
Elderton: Pushing my luck with this one, as their wines are typically priced above my C$20 cut-off, but their "Friends" line of wines are good values and should be found under the price cut.
Greg Norman: Ok, I'll admit that I have avoided his wines because I figured any golfer's wines are hype, not substance. I will also admit I was wrong. The wines are typically pushing against my price target, but should be available at that magic C$20. Look for the terrific Chardonnay and Cabernet-Merlot. I can't comment on his California stuff.
Penfold's: They make some good high-end stuff, but their Koonunga Hill range are great values, especially the Shiraz-Cabernet.
Yalumba: Their "Bush Vine" Grenache, Barossa Shiraz, and Shiraz+Viognier are amongst the best value reds on the planet, widely available, and consistent year after year. Their Eden Valley Viognier is one of the most interesting inexpensive whites I have ever tasted. And their expensive wines are pretty good too! It gets even better - their Y series wines are even cheaper, and even better values (I like the Y Merlot).