I live in the city and use SJC a lot. Usually just rent a car at SJC and drop it off an hour later (or the next morning) at one of the Fisherman's Wharf locations. Cost varies by day and week (presumably according to demand and inventory). Usually about $40-$50 OW. From Daly City, BART to SFO and the Monterey Airbus sounds like a pretty good deal, although running every 90 minutes, you might be waiting a while.