LMI has a good selection of high quality bridge pins. Stew-Mac doesn't carry rosewood pins for some reason. I've had no luck with Chinese suppliers on ebay, which don't seem to know the difference between MOP and abalone dots.
If you are up for at least 1/2 gross then Gurian Instruments is the place to go. I'd venture a guess that places like Stew Mac and LMI get theirs from Micheal.
I've got several sets of very nice rosewood pins from the Bezdez store on eBay Canada (http://stores.ebay.ca/bezdez/). Shipping was kinda pricey, but all in all I didn't spend any more than if I had bought them locally for three times the price per set.
If you are up for at least 1/2 gross then Gurian Instruments is the place to go. I'd venture a guess that places like Stew Mac and LMI get theirs from Micheal.