Most listings are in the $10's per square foot per year. The Twain submarket is going through a a rise in rates. In the last 3 months, the median rate increased $3 per sqft per year. That's a 22% increase in rent.
In the last 90 days, 8 listings have come on the market, which means new listings are probably going fast. You'll want to be prepared to tour spaces as quick as possible. About 13% of the available leases in the Twain are subleases, so you might be able to sign a shorter term by taking over a previous lease. There aren't many listings below 2,000 square feet on the market, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 1,190 sqft. Most buildings in this area are around 2 stories. Most buildings in this region were built in 1989.