I just got one from eBay, well it's in the mail. I actually got 2. A 60mm and an 80mm. Both under $A20. I looked at the ones on Amazon, but all the ones I found didn't ship to Australia
I had a 50mm on before and I got my 110mm today. I just love them! I got the smaller one from a gift shop here in town and the larger one I got from amazon.
I got mine from Amazon (there are many selections, very well priced): http://www.amazon.com/s/ref=nb_sb_noss_1?url=search-alias%3Daps&field-keywords=crystal+ball&x=0&y=0
I just went to ebay and searched crystal ball, there were quite a few sites that had them. From China