Thanks for asking your question.
La Jolla, Poway and Rancho Bernardo all have great school districts, one of the best in San Diego County actually.
La Jolla, being a very well off neighborhood, is super nice, with lots of restaurants and things to do, as well as parks, recreation areas, beaches, etc. But you are correct, the prices there are pretty steep. Depending on what you want a house or a condo, for a single detached home you'll end up paying a million and up.
You can definitely get the same kind of home in Scripps Ranch for much less, so I recommend you exploring both areas.
It would be a great step to drive through both neighborhoods and start looking at some sites online for property prices, etc.
Find a realtor you are comfortable working with and that is knowledgeable about those areas and start the process with him/her.
Let me know if I can help you in any other way,
Sincerely,Real Estate Supergirl
Allison James Estates and Homes
7 Horton Plaza,
San Diego, CA, 92101