I used to think I was so smart renting a high end home from someone that was losing $3k a month, but over time, rent vs buy in San Diego has been a losing bet. Even the $1M-$2M homes are now cheaper to own, or at worst, break even. A newly remodeled $1.4M ish condo or home in La Jolla or PB will cost you $5-6k plus a month to rent.
I think you can pretty much buy anything in the county with 20% down and it will cash flow. 10-20 years ago it took 30% to 50% down.