If I may ask, what is the cheapest health Ins plan? (medical, hospital)

[Art2ro]

From what I've seen and read, the cost of health insurance are different from state to state and or regions! Can one purchase health ins from another state other than their own?
Also government run group health insurance also has lower monthly premiums, but I don't know if they any lower than that those of the private sector!
It is pretty overwhelming in looking for the most appropriate health ins coverage for one's family at the right affordable price!
Also, what U.S. health ins plans can be used overseas without any out of the pocket expenses? I know Blue Cross Blue Shield for inpatient care is one of them and they have premium rates!
We used to have Kaiser of Northern California and their premiums rates are high now, so we therefore I suspended them and switched over to TRICARE Standard when I retired from the military and moved overseas! The drawback to TRICARE overseas is that the hospitals overseas only accepts upfront cash payments in full for medical services rendered and of one's purchase of their prescription drugs and one has to submit their claims to TRICARE WPS for a 75% reimbursements of the costs we paid in cash which are sometimes denied or under paid after the claim has been approved, it is not a good program for those living overseas other than the fact there are no TRICARE monthly premium costs while residing overseas! And Medicare is not available overseas, but TRICARE will pickup the cost, I think that's how it goes anyways!
So, what are your experiences with your medical health care policies or issues in your state or country one is living in for retirement?
I'm just overwhelmed and curious to know from other people's experiences.
Thanks in advance!