If you look at Southern California regionally, San Diego is probably the least expensive place to buy a house within 5 miles of the coast and still close to job centers.

Coastal areas away from job centers might have the same climate, but not the same amenities and attractions (pro sports, night life, etc).
So, I guess southern California is out.
I don’t see any other parts of the country having the exact same qualities.

So, it all depends on what is most important to you in term of “quality of life”.

If it’s solely the climate, and being close to job centers and amenities of a large city are secondary, I am sure you can find some places in Ventura county that would suit you.