Ah man! I bought Masterclass from them a few months back but I didn't see that discount. From what I remember, they didn't have much else in the way of trad CD's. One site I highly recommend is Skinnyfish Music located near Darwin. They have all the Garma CD's, both the White Cockatoo, Jutbirrk, Rak Badjalarr, and Wurrumiri-Kunborrk...so its a good one-stop shop if you are just starting out and want to get everything at once from the same place. I was a bit apprehensive about sending money, but you'll get your stuff in 2 or 3 weeks.
Hey, thanks for the pointer! They've got pretty good prices -- Correction: GREAT prices (free shipping to the US!) -- on the Djalu CDs so I'm going to order them.