I purchased luster dust and petal dust from an Ebay vendor, Jesters Party Supply:
http://cgi.ebay.com/Fuschia-Petal-Dust-Gumpaste-Decorating-1007_W0QQitemZ190026577765QQihZ009QQcategoryZ46281QQcmdZViewItem
The luster dusts are $2.49 ea. and petal dusts are $1.99 each. They will send as many as you want for $4.05. I bought a combo of luster and petal--22 pots (all different colors) in all--for a total of $51.83, shipping included--$2.36 ea. I just find that this stuff goes such a long way that for things other than super pearl, I would prefer not to have duplicates.
The order was sent well packed and very quickly. They also have a website: Jestersparty.com . The shipping terms aren't quite as clear on that site, but in general they promise to send as much as possible by the least expensive shipping option.
Rae
I got mine from Payless... I couldn't be any happier.. I am very satisfied..
it's $2.98 of a two pack, very good quality that's why I bought 34 jars.
I got all LUSTER not petal.. I like the shiney ones. 
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