I discovered today that RDU-TPA has a fare in which US Airways has matched Southwest's full fare ticket. It's a bit tricky to find, as you must search by unrestricted coach fare. The reason I never saw it is because it is an L fare, not a B fare (as most of these are). It is LRQ3. Completely refundable, unrestricted coach ticket. Comes to about $257 roundtrip after all taxes ($228 base). Good deal IMHO.