I haven't purchased commercial sex in a long time, and I've never done so in Austin, but from what I'm aware, Austin isn't the best market.
There's a small streetwalking scene that I understand is a little scary.
There's also a few AMPs, including the famous Midnight Cowboy on 6th Street that never seems to get shut down despite being in the middle of the touristy district.
There are a few indies but I've never heard of any of them being really great.
It used to be that a few of the Houston agencies would send girls down to Austin, so you might want to look into that.
Then there's the Laredo Boystown which is a few hours away on the other side of the border. I used to like going there, but the last person I sent had a bad time. I think it might help to know a little Spanish. Anyway, I think it's worth going to for a whorehound as just an experience if nothing else.
The best public site for whoredom in Texas is probably still ASPD.net.
If you're at all young (under 30) and good looking, you might want to troll the bars downtown. The three main areas are along Red River between, say, 9th and 5th; 6th street from Red River to Congress; and the Warehouse district between 4th and 5th and Lavaca to Congress. The first area is mostly punkish alteranakids, the second is fratish type college students, and the last is where the yuppies hang out. Prices and ambience vary accordingly. Anyways, Austin is pretty much filled with young, beautiful women that surprisingly will have sex without demanding money. Although you might have to sith through their discourse on Ayn Rand.