Cheap Insurance: Saving Money or Playing with Fire?

Backstory: I recently left my job with a good amount of money saved up, which I’m planning to rely on for the foreseeable future as I pursue my own ventures. Since I don’t expect many doctor visits next year and am fine paying out-of-pocket for those, my main goal is finding an affordable insurance plan that protects me against catastrophes that could deplete my savings, or even bankrupt me.

Concern: If something big goes down, I don’t want to be left with any part of the bill beyond my plan’s maximum. While the out-of-pocket maximums seem to suggest I wouldn’t pay more than about $9,000 annually, I’ve come to understand this cap only applies to the amount that my insurer agrees to. So if I were treated at an out-of-network hospital and the bill was $500,000, but my insurance valued the treatment at $300,000, I could be liable for the $200,000 difference (this is called balance billing). It seems to me then that having a wide network is crucial to avoid this scenario. Basically, I want to make sure if I end up at an ER, it is in-network and fully covered. Is my understanding on this correct? Is there anything I’m missing? Denial rates is probably another important thing to consider as well.

Options: Ambetter offers the most affordable option at $150 per month, though it has a very limited network. United’s cheapest plan will cost $300 per month, but has a much wider network. Premera, at $400 per month, seems to be the most widely accepted provider. I’ve also personally had good experiences with them.

I can afford the premera plan, so should I just go with that? I want to insure myself from financial ruin, and it seems like the premera plan is the safest way to do that. Any advice or insights would be greatly appreciated.