The typical asking rate per listing is in the $0's per square foot per year. The Harlingen submarket is seeing a decrease in rates. In the last 3 months, the median rate fell $16 per sqft per year. That's a 100% decline in rent.
In the last 90 days, 3 listings have been listed, which means new listings most likley are going fast. You'll want to be prepared to tour spaces as quick as possible. 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 sqft. Most buildings in this market were built in 1999 and are Class A.