the problem here is if there are competing neighborhoods that are in better school districts and with real or perceived desirability, with pricing point very close to Skyranch, Skyranch will not be able to compete.
the price point for close to 4000 sqft sfr in 4S is now low 700s. there are way too many listings to count for homes from 3000 to 4000 sqft, ranging from pedestrian to grand. in Santee there’s a single listing.
as for the above 4000 sqft market, you got Stonebridge with 3 new home builders with some offering homes in the low 800s. yes granted one would have to spend another $200k to dress up the new home, whereas the Santee example you listed is already fully decked out. but I think the Scripps address and the Poway schools will be too overwhelming to fight.
at the end of the day, if someone has the ability to buy a 800k home, they will rather go for 4S or Stonebridge and Santee will not be on their map at all.
I think ultimately the $400-500k market is the Santee niche. and that is not a bad place to be.