Right, right. The flights are available at Saver through US Airways and AA.
I did the math and decided just to pay cash for a similar Southwest flight on the same days. Using the SW price (which is lower than the US price) and 9,000 Avios, I would only get 1.6cpp in value anyway. Plus, the SW airports are more convenient.
If anyone does end up calling, I'd be curious to know whether they allow you to book, or if US Airways Avios awards are more restricted than awards from other programs.