Most listings are in the $20's per square foot per year. The McAllen submarket is experiencing a a rise in rates. In the last 3 months, the median rate increased $6 per sqft per year. That's a 24% rise in rent.
In the last 90 days, 27 listings have come on the market, which means new listings most likley are leasing quickly. You'll want to be prepared to make an offer immediately. 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 920 sqft. Most properties in this region are approximately 1 stories. Most buildings in this region were built in 2001 and are Class A.