Really depends on your goals in life, among other things.
We live in Coastal So Cal, definitely a HCOL area. We managed to live frugally because we're frugal, and because my husband was in grad school. That meant small apartments, and eventually student housing. We had only one car for awhile and tend towards smaller cars anyway.
The thing is, we never planned to stay, but the grad school took 7 years, and then we stayed. I would counsel people to avoid them too, in many cases.
But in the tech world, sometimes that's what you have to do - live in Bay Area, or whatever. And now, I love it here.
So housing is the worst, and we timed it poorly (bought in 2004, house still worth less than we paid for it). Bought small, plan to stay here. Bought knowing we'd both be working (because we like it!)
The thing is to try to avoid the other high cost traps. With kids and jobs, daycare is unavoidable, but the uber high class crunchy preschools are not. Summer camps start at $150 a week and go to $400 a week. Guess which ones we pick? Eating out and shopping at the farmer's market and at whole foods are what the cool kids do. We try to limit our eating out and use a CSA and shop better. (However my spouse does eat out more than I'd like.)
I'm happy with the life I have, but I understand it's not for everyone. If you would prefer a bit more of a downshifted life (one parent at home with the kids) then I'd counsel against HCOL.
"Be the change" - offer up baby sitting swaps, have your friends over for dinner or for parties. Instead of going out to dinner or concerts, my spouse and I will have lunch together, or go to free concerts. Instead of meeting our friends for dinner on Friday nights at kid-friendly places, we get together with OTHER friends who have pot lucks in the park (yes, it means I am choosing specific friends to hang out with more). Instead of taking the kids to the trampoline place, we meet other friends at the zoo, the park, or the beach. Instead of having a "girl's lunch" with my friend with 3 kids, we've started meeting at the gym.
Tonight's entertainment, instead of something that costs money, is:
1. Grad party for the friends of the potlucks
2. Mom's game night party <- I wish I could take credit for this. Our toddler mom groups does occasional "mom's nights" out with dinner and drinks. And these are expensive. I am only likely to go 1-2 times a year. One of the moms is having us over for a game night. We bring drinks, snacks, games. I personally am taking soda water and popcorn. I can't drink and drive anyway.