4s Ranch has 4 bed 1900-2100 sq ft for less than 550 (look for La Vina – saintsbury glen/ tallus or Garden Gate – calloway/snowbell/etc). Probably will get smaller lot there but will be an easier commute for you.

Regarding schools, scores change rapidly. Some of the usually low scores are improving in areas like san marcos (fed by parts of carlsbad zipcodes). Keep this in mind when you look at eastern carlsbad.