It’s expensive because there is demand for the area – freeway close to both I-5 and I-15, good schools, moderate temperatures (much cooler than Scripps Ranch on a day like today), new neighborhood. Yes, the Mello-Roos are very high.
4S Ranch is farther commute for most people, so it is perceived as less desirable. Do you like Carmel Valley but prices are too high? Do you like Torrey Highlands? Here’s a 3800SF for $780K, if you add the landscaping and interior upgrades, its almost back to 2003 pricing. A lot lower than CV prices.