I'm not in california, but my machine shop charged me 300$ for a PAIR of chevy heads to be rebuilt + parts cost. In the end for all new retainers, seats, springs, hot tank, decked the head & 3 angle vavle job + 3 valves it was 600$ These parts were for a race motor too, not cheap oem replacements.
I strongly reccommend searcing your area for an actual machine shop and go there.