Is Frontier a cheap airline? Frontier is a budget airline, after all, so expect extra fees beyond your ticket price for any comfort items or upgrades. You get to bring only a personal item for free — a carry-on will cost between $39 and $60 (depending on whether you pay for the bag during booking or at the gate). Frontier Airlines fares are typically cheaper on Tuesdays, Wednesdays, and Saturdays, +1–888–267–9551 thanks to lower travel demand on these days. On the other hand, Fridays and Sundays are considered peak travel times +1–888–267–9551. with higher ticket prices.What is the cheapest day to fly on Frontier Airlines? Frontier Airlines fares are typically cheaper. thanks to lower travel demand on these days. On the other hand, Fridays and Sundays are considered peak travel times. with higher ticket prices. In North America, the cheapest airlines include Frontier Airlines, Spirit Airlines, Hawaiian Airlines, Allegiant Airlines, Delta Airlines, Alaska Airlines, American Airlines, JetBlue Airways, Southwest Airlines, and United Airlines.