If I'm down in Hobart anyway, I'll stock up on some spec malts in 5kg lots - they are pretty good value for non-bulk buys.
But getting involved in the bulk buys is a big thing for me - it saves a packet of money.
Hops - generally via Yob at hopdealzaustralia.com. Before he came along, I'd get larger quantities from the US from Niko or Yakima valley hops, but with him there, I can get almost bulk buying prices without kgs of hops sitting in my freezer for too long.