Check out this this spreadsheet at HHS - It's gigantic and if there's a way to replicate it in case it disappears, I don't know how. At least for Virginia, where I live, the prices vary, and are listed by, county or city.
I believe, although I'm not positive, that this is the set of premiums discussed last night on Mark Levin's show - the "age 50 or above" figures are based on age 50 and the "age 49 or below" premiums are based on age 37. Therefore, since your premium will vary by age, if you are (for example) 45, the "49 and below number", which is really for 27 year olds, will be much lower than your actual premium. Same thing if you're a 60 year old looking at the "50 and above" numbers.