I have one group practice hiring contact that quotes me a $125 per hour all inclusive excepting malpractice. This again roughly translates to 200k. Not sure what their partnership track is like, but I explored it and believe that I can make a lot more in solo practice per hour if i only have a part time practice.
400k*0.8-80k overhead = 240k
The timing for filling cash practice depends on a LOT of things, and I do think credentialism is alive and well in expensive markets, though the exact size of that effect is difficult to quantify. Some people may never fill 100% cash. Some people may fill under 6 months. It's just very hard to say. I'd say if you take insurance you should fill within 6 months.
I go to a "top" program but don't live in NYC. I'm familiar with NYC, DC, Boston, SF and LA, and the quotes are roughly similar with prime Manhattan being slightly higher than everywhere else, but not much higher (at most 3-5%, maybe 10%?) than say Georgetown or Pacific Heights. Chicago is lower, but still doable. Nitemagi, you are right it's hard to charge $400 for 45min therapy, but I don't think it's rare for people in wealthier parts of LA to charge $200 for 99213+90833. I've heard it and seen it. Two of those you get $400 right there. Houston is also a great market for this kind of setup.
A different way to think about it is if you have decent out-of-network coverage, say BCBS, deductible is ~$2000 a year, unlimited visits, 80% coverage for "usual-and-customary" can get you $250. For once weekly therapy, you MAX out at 2k a year as a patient. A LOT of angsty young professionals are willing to do this kind of thing. A lot of them also need meds.
Vistaril, you should move. You are right it's hard to charge $600, but senior people do it routinely. It's really a different world out there. On the other hand, you can probably get two beautiful houses around where you live with a 200k salary. The other thing is to consider certain "under-exposed" wealthy areas which I think have huge potentials. Texas, as I said being one. San Diego I think is another. I bet you can do really really well working cash in La Jolla.