You're in a tough situation because no one has any relevant personal experience for you, because the nature of getting private insurance for those years between FIRE and Medicare eligibility is changing effectively January 1.
Having said that, you may find this calculator useful:
Subsidy Calculator | The Henry J. Kaiser Family Foundation
I entered an arbitrarily high income amount and found a 62 year old non-smoker can get a Silver plan for $8,671 in 2014. A Bronze plan would be a bit less. A Gold plan a bit more.