American Airlines have round trip airfares travelling to and from Pittsburgh (PIT) and Los Angeles (LAX) for $142, making 1 stop. For price comparison, Spirit Airlines have a nonstop for $258.
Travel Availability: August thru January, mid-week and excludes holiday season.
To search and book for best dates, go to Skyscanner [skyscanner.com]
and view 'whole month'. It aggregates the latest prices and select your favorite OTA to book. For this particular fare, I chose to book directly with AA via Skyscanner.