Frontier is not our favorite airline here, but we have to hand it to them – several of their fares are just very attractive.
These routes in and out of Denver price out at $38 return or $58 return:
Atlanta – Denver
Austin – Denver
Frontier charges $25 for a checked bag (at the time of web check-in) or $30 for a carry-on.
So unless you have no luggage at all you, will pay a bit more, but for the ~1,800 miles RT Houston to Denver this is still an awesome deal and maybe worth putting up with the Frontier rules and luggage drama.