Dennis,
Smart and Final generally has them. They're all over the Bay area. Last week Smart and Final had CHOICE grade briskets for only 1.39 a pound. That's a great price for a CHOICE grade. Typically, they stock Select grade briskets, which run 1.05 to 1.15 a pound. I've had good luck cooking select grade briskets, you jut have to cook them a little longer before they become tender. Choice grade has more marbeling and is more tender and juicy. But done right, those select grade briskets turn out just fine.
I hear Sam's club has them sometimes too, but the closest one I know is out in Concord.
Otherwise, find a good butcher in your area and they can order one for you. Ask for a whole, untrimmed brisket, including both flat and point sections. Tell them you want it the packer cut style, preferably still in cryovac. The more detail you can give the butcher, the better. Some know right away what you're talking about. Others don't, but when they talk to their meat supplier the right thing usually shows up. Butcher shops tend to be more expensive than Smart and Final. So be prepared to spend a little more per pound.