Why does the same size AC unit cost more near the Oceanside pier than in East Oceanside?
It's not the unit, it's the spec. Strand and downtown properties near the water need coastal-rated condensers with corrosion-protected coils, typically $400 to $1,000 more than standard equipment, while East Oceanside homes need standard-spec equipment sized for higher inland cooling load instead. Both add cost, just for different reasons.