Most listings are in the $20's per square foot per year. The Bexar County region is experiencing a a rise in rates. In the last 3 months, the median rate rose $1 per sqft per year. That's a 6% rise in rent.
Compared to the rest of the Greater Austin market, the Bexar County submarket has lower rates, so you should have no trouble finding a great deal in this discounted region.
In the last 90 days, 712 listings have been made available, so you'll want to check back regularly for new listings. About 2% of the available space in the Bexar County are subleases, so you will probably have to consider a longer term lease. 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 2,195 sqft. Most properties in this market are around 2 stories. Most buildings in this region were built in 1985 and are Class A.