You are in Southern California. These are not unreasonable fees. You are right in doing the bottom while it is out, you won't have to touch it for a few years if you use a monthly dive service. Obviously the yard wants you to buy
paint from them, so unless you have a killer deal on
paint, go ahead and do that and avoid any extra fees. Just out of curiosity, is this at LB Shipyard? Have you tried Colonial?