Glass Brokers Inc. is the direct distributor. They prefer to sell in tray lots (45 pcs. of 150gram, 28 pcs. of 300 gram, 24 pcs. of 400 gram...) but you can buy by the piece, too. 8 pieces minimum for 150 gram, and 4 pieces for 300 and 400 gram. The prices per piece when you buy by the piece are $10.50 for 150 gram, $21 for 300 gram, $28 for 300 gram including domestic shipping.
www.glass-brokers.com
glassbrokers@adelphia.net
570-602-8833
I use a diamond saw to cut them.