I, personally, find the whole "HCOL"/"LCOL" distinction and the obsession over it to be fairly meaningless.
I have traveled extensively across the country for work. From what I have seen, you have many more opportunities to save in the HCOL's and VHCOL's on the eastern seaboard than in the LCOL's in midwest, south, or non-metro northeast locations.
The *only* cost that are really lower in LCOL's is the housing. Everything else seems to cost higher in LCOL locations!! I can coupon and comparison shop the heck out of it where I live. There are 5 big grocery stores within a 1 mile radius of my home, and 3 CVS's, 3 Walgreens, 2 riteaid's, and a couple of holdover mom-and-pop drugstores from the nostalgic yesterdays. Something similar was true anywhere else within the NE Corridor I have lived in (including NJ, Phily).
If you are in NYC proper, then you got the Indian stores in Queens, or Chinese stores in both Chinatowns with amazing prices. You don't need coupons if you shop there for produce. Takeout food is also way cheaper than anywhere else. To top it, you don't need a car if you live in NYC proper. That is almost $3k/year saving right there per my calculations.
If you are creative, you also don't have to pay the cutthroat housing costs. I don't. I live a 90-minute commute from Grand Central, work from home a lot, and paid < $300k for a house with a reasonably good school district. The towns and cities are not so cash strapped like the midwest towns. It runs a budget surplus. There are frequent events organized on the town green - which are amazing free entertainment opportunities. I can (and have) petitioned the town to get budget allocated to something different - because there *is* headroom to allow it to do so.
When people talk about saving money by moving to LCOL areas, I don't quite see how the math works out there.
Granted, I know nothing about Cali. Never lived there and only made some short trips there.
<edited> Corrections. I don't quite have 10 big grocery chain stores within 1 mile. I have to increase the radius to 3 miles to hit 10.