The typical asking rate per listing is in the $20's per square foot per year. The Greater Austin submarket is going through a a rise in rates. In the last 3 months, the median rate went up $1 per sqft per year. That's a 2% rise in rent.
In the last 90 days, 1138 listings have been listed, so you'll want to check back regularly for new listings. About 9% of the available leases in the Greater Austin are subleases, so you will probably need to sign a longer term lease with the landlord directly. There aren't many listings below 2,000 square feet posted, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 2,500 sqft. Most properties in this region are approximately 2 stories. Most buildings in this market were built in 1986 and are Class A.