Don't get me wrong, Austin is a much better city for the average person to live in. It's a nicer looking city with a great atmosphere, with lots to do. Just like there are nicer cities to live in than NY and Chicago.
I just think that if you are a trader or work in the financial industry, you will be better off in Dallas over Austin from a career standpoint because all the firms are here. This creates a constant stream of candidates and turnover from all these firms that a prop shop could get access to. People hate to relocate. You become attached to your city through friends, associates, family and just the overall history of the town.
Honestly there are much better places to live versus Austin or Dallas if you are looking for lakes, etc. And I don't know if that would justify a business venture.
If you are genuinely looking to open up a prop shop, you need to be confident that you will have a good source of traders from the existing job market in your area and you want to be in an area where there isn't much competition as well and Dallas is perfect for that.
I think you would have better luck pulling from a larger pool of industry professionals. Having a prop in Chicago and NY makes sense for the same reasons. The only problem is there is a lot of competition in both areas now.
So if you look south to Texas and think, "how can I capitalize on that region" you first should look to see where all the firms are again. There is a reason why there are so many hedge funds, mutual funds, trading firms, and large financial offices in Dallas. And that reason is because everyone else is here! I know that sounds like a silly reason to put up a firm but it's why it happened in NY and why it happens in Chicago.
Dallas is a large city. You don't have to put the office right in down town. You could put it slightly outside the city if traffic is a big issue. Fort Worth is about 15 minutes away from Dallas and doesn't have nearly as much traffic as Dallas. And there is a lot of money in Fort Worth as well near the South Lake area. Ross Perot owns a lot of the land out there. Maybe you can work out a deal with him?
Let him trade in your shop in exchange for some land maybe. That should bring in some spectators to watch.