Here's another "buck sale" from Frontier. Base fares of $1 each way add up to $39 roundtrip after taxes and booking fees. Choose from around 50 routes at this incredibly low price.
Availability is limited so you must be somewhat flexible to find the lowest price. Travel days will vary by route, but generally fares are available between August 14 and October 3. Pretty much all of these routes are only flown a few times each week so be sure to check out the specifics in the fare details on your route.
Tickets must be booked by 11:59 pm ET, on July 25, or before seats sell out.
These fares all work in reverse as well. You'll have to decline all extras to get the lowest price.
Keep in mind that Frontier charges extra for any bags larger than a small personal item (small backpack, purse, etc.). Pack super light to get the lowest price. Checked bag fees start at $25 each way. Larger carry-on bag fees start at $30 each way.