WW2's statement as to what has passed in California is wildly inaccurate, but beside the point. Yes, there is one new ammo bill (which hasn't yet been voted on by the Assembly, but will pass, and then on to the Gov, who may veto as he has done before), and one ballot proposition, the latter of which is excruciatingly draconian, and does include an ammo license (with background check), a vendor's license, sales only in face to face transactions (with a NICS check), a ban on shipments into the state except if processed by a licensed vendor (with a NICS check and of course for a fee). The Senate bill, which is intended to undercut the ballot initiative, does require a face to face transaction, vendor (but not purchaser) licensing, and the recording of information as to buyer, buyer ID, and ammo purchased.
MEANWHILE it is perfectly legal for a California resident outside of enumerated cities to purchase ammunition from on-line vendors. I personally have been buying from Freedom Munitions, which has excellent prices and high quality ammo. Lucky Gunner is another popular source. I don't remember what I paid for .357, but it was less than .40 per round. 9 mm was under .30 per round, I'm thinking maybe .26. Many of these places have low or very reasonable shipping costs. For example, Freedom Munitions right now is $7.50 for orders over $99