I buy at Humble Abodes Inc.! (9-1/8" Grooved top and bottom unassembled frames) $0.65/each in lots of 100 or $0.63/each in lots of 500 (thair as no free S+H)
http://humbleabodesinc.com/index.php?main_page=product_info&cPath=2&products_id=12
BEE HAPPY Jim 134 :)
It all comes down to shipping costs. I'm sure the shipping on 100 frames from Humble Abode is more than $7. I'm sure there are plenty of places that have frames listed cheaper, I use to buy from Beeline, but when you add shipping into the total cost, they tend not to be such good deals.