I think you are right that many young couples with children or planning to have them are willing to pay a little bit more to live in an area like Carmel Valley.
I have a friend who purchased a house for $590K (~1700 sq ft) in the Calle Cristobal in Mira Mesa in 2005. Now his daughter is 4 yr old and he thinks that the schools in Mira Mesa are average at best. He wishes that he could have waited a little bit so he could buy in Scripps Ranch or Carmel Valley.
Because school is such an important issue for many, I think that a decent SFH (~1500-1700 sq ft) in the 500s in Carmel Valley will be a good buy for many people so prices might not go under 500K for this area any time soon, and probably never because once it is around 550K we and many other people will jump in.
