https://sfbay.craigslist.org/sfc/mod...027632637.html
I've bought a phone or two from these folks and recommend them highly. Worth a trip to SF.
(No vested interest in suggesting them.)
Locally, the kiosk closest to Macy's in the downtown mall is fabulous for battery exchange and repair.
Luis is great - you can give him my regards. (Also no vested interest in recommendation.)
Best, Jude