Fly for a "buck" plus taxes/fees on Frontier Airlines on a few select routes and dates. Though we have seen this sale on a nearly weekly basis lately, we do see a few new routes drop to this rock-bottom price each week. Roundtrip itineraries are available starting from $39 and many routes can be found for under $100 roundtrip.
The sale is advertised for travel Mondays through Thursdays, and Saturdays, through June 19, 2019.
Most routes are only flown on specific days of the week so you'll have to click around to find available flights. A 3-day advanced purchase is required.
Tickets must be booked by 11:59 pm ET, May 15, 2019.
All fares are nonstop and work in the reverse direction as well.
There are many more routes available for under $100 roundtrip. Lowest fares may not be available throughout the entire travel period. You'll have to decline all extras to get the lowest price.
These fares only include one small personal item. Checked bag fees start at $30 each way when purchased during the initial booking. Larger carry-on bag fees start at $35 each way.
Seats will be assigned at random upon check-in for these prices. You may pay a fee to choose a specific seat.
Frontier offers the Works bundle, which can be added to any flight during the initial booking. It includes a standard carry-on bag plus a personal item, one free checked bag, seat selection (including stretch seating), priority boarding, flight flexibility, and refundability. This is a value if you want all of these amenities, but chances are you can get away with just adding what you need a la carte for cheaper.
Searching Frontier's site, I found flights departing Charleston CHS on Thursday, May 23, returning from Philadelphia PHL on Tuesday, May 28 for $39 roundtrip.