According to zillow

http://www.zillow.com/homedetails/3228-Carleton-St-San-Diego-CA-92106/17063600_zpid/#{scid=hdp-site-map-bubble-address}

there were two side by side lots for sale.

Also, if you look at zillow

http://www.zillow.com/homedetails/3226-Carleton-St-San-Diego-CA-92106/99527574_zpid/#{scid=hdp-site-map-bubble-address}

the adjacent 5k sq. ft. lot at 3226 Carleton just sold for 190k in June 2011 (sold for 506.5k in 2005).

So the buyer of 3228 probably paid 190+265 = 455k for both lots. Still a pretty good price for a 10k sq. ft. lot in that area with those views.