If you don’t have to worry about the school district, why buy in North County at all ? I have no idea. Maybe Encinitas or Leucadia if you don’t have to work every day.
If you don’t feel the need to be close to LA, I’d suggest looking in University City or Bay Park down in the central part of San Diego.
University City has some great 50’s homes (which I like as they are built well) in really nice neighborhoods. No HOA/Mello Roos either. For the same price, compared to Oceanside, you would probably get a smaller house, but it would be closer to more fun “San Diego” things like Mission Bay, La Jolla beaches, and Downtown.
Bay Park and Bay Ho have remarkable views of Downtown and Mission Bay. Sometimes the sloped lots force you into a deck instead of a yard, but other canyon/view lots can be stunning.
I think a million in either place would get you a good house on an awesome lot.
Some say the three most important words in real estate are “location, location, location” but I’m starting to think they are “space between houses”. So many new developments build them soooo close together.