You'll probably be in the $130-150/sqft range in Riverside Village. Of course that depends on the upgrades, size, lot size, location, etc that you get too. You can spend more and perhaps less. You'll probably do better on a house that is built and someone didn't close, than attempting to negotiate a new build. The builders did pretty well in La Villita. The location itself is decent, but I'm not the biggest fan of the lot layout and all the big powerlines around it. They also seem to be building some pretty big houses on small lots which may give the neighborhood a funny feel. Time will tell. The problem is if you want new construction, there's not much to choose from. University Park may be an option...there's still a few new builds in La Villita.
My advice is always use a realtor to help you negotiate with builders. The builders pay us to represent you and fight in your corner. We haven't seen so many questions about problems with builders lately, but for a long time on this forum we saw problem after problem after problem of one time buyers. There may be some other options around depending on what you want to pay and what you want. Resales may also offer a better value...even after just 1-2-3 years old.