I went through the same issue. I live in Texas, and my wife's best friend's sister is a surgical nurse at HEI. Of course, the nurse said I had to get it done there. Dr Friedman was the doctor. Same "out of net work" issues popped up. Not willing to risk my retirement on a lot of unknown cost, I started looking for a local surgeon that could "cut and paste" on my old head. If you go to HEI, they want you to stay for 2 weeks. Through some contacts on this site, I found a great doctor in Houston, was in the hospital for 3 days, and went home as a happy camper.
I certainly won't knock HEI, but with a little bit of research here, you can probably find a local doctor that can do this surgery. I found 2, and one wanted to do radiation, and one thought surgery was the answer. HEI recommended surgery after looking at my MRI. I would have been perfectly happy with either doctor locally. Do a little home work and think about staying home. You can interview the docs and I'm sure you can draw your own conclusions.
The idea of being stuck in a hotel in LA to recover did not sound very inviting to me...for 2 weeks. My own bed was a great place to recover. My wife's cooking beats anything a hotel can dish out. I could sit out in the back yard and watch the river roll on by. Home is a great place to recover...and I had no "out of network" expenses, and I am retired without all of that debt.
James