Fly from Pittsburgh to Oranjestad, Aruba for $309 roundtrip through March on Delta or United Airlines.
Searching on Delta, I found seats departing PIT on Thursday, December 6 and returning from AUA on Thursday, December 13, 2018. Flights are available daily, but you will have to be flexible in some months, travel is easier to find in 2019 as people haven't book out that far in advance yet. That's a perfect time for a sunny escape from the Pittsburgh winter.
These fares book into Basic Economy which limits your baggage to only a carry-on. Checked baggage will cost additional. United Airlines baggage restrictions are more strict than those of Delta, so be aware of that if you choose to fly with them.
Have a look at all the daily deals we have found departing Pittsburgh PIT here.
Need a room while in Aruba? Here's a list of hotels available for the listed dates on Hotelwatchdog.