When the new Australian kilo coins come out there are usually some pretty good deals. I don't remember the exact price I paid, but I'm pretty sure a few of the kilos that I bought were under $700. I sold a couple duplicates off recently, and it actually took some time to get the $700 price I wanted per coin. As mentioned, most people want smaller, less expensive silver coins.
I love them though, they show the detail in way that small coins just can't. It's like bullion and art in one!