Since I don't really have a sense for the size of the houses in SF, I'd be interested to know how SF's numbers for "$/sq.foot of floor space" and "$/acreage" compare with places like Palo Alto.
http://pricesquares.com/#/county/1/san-francisco/
You can see that the north and northeast portions of the city carry the highest rates (close to $1k/sq foot in Pac Heights and the Marina).
Zoom in to drill down to smaller neighborhoods/sub-districts.
For comps between SF and Palo Alto, I'd recommend Redfin. Last I checked, the Palo Alto prices were above SF prices (on a square foot basis).
Edit: I'll just add some more detail!
Here's the Redfin report for Palo Alto ($1,168/sq ft): http://www.redfin.com/city/14325/CA/Palo-Alto
Here's the Redfin report for SF ($660/sq ft) http://www.redfin.com/city/17151/CA/San-Francisco
http://www.zillow.com/local-info/CA-home-value/r_9/#metric=m...