I have been looking in these areas for a year and a half – in the same price range as you. My target is actually $750K by end of next year.
La Costa Greens – San Marcos school district other than that little pocket north of Poinsettia. I would rather live in SEH.
Other areas you should consider are Mariner’s Point, The Bay Collection (poised for a beat down soon), and Santa Fe Trails.
I agree with your 100K comment but I look at it a different way. My range hasn’t changed but the quality of house/hood I get for that has improved significantly. I used to pray for SEH at $700 – now I see Aviara, LCV, or SFT easily there in the next 12 months.