http://www.gunsonthenet.com/
http://www.auctionarms.com/
these are a sort of ebay for gun owners. unfortunately, california's laws make it a pain in the ass to buy from out of state. but they're nice places to window shop, and see what prices are.
you can get a really nice shotgun for $500. great for home defense. take the kids out to shoot skeet. maybe even some hunting.