I was poking around and saw Frontier Airlines has flights for $14 each way between Pittsburgh (PIT) and Orlando (MCO) on Tuesdays and Thursdays.
PIT-MCO is 10:36 am - 1:05 pm daily.
MCO-PIT is 7:09 - 9:35 am daily.
I'm seeing $14 flights most Tuesdays and Thursdays through January 2020 on Frontier's website. There are some exceptions. Hotwire and Priceline are charging $20 for the same flights. I'm not sure if this is a sale or regular fare. It's Frontier so they'll nickel and dime you but it can be a great deal if you travel light.