The typical asking rate per listing is in the $20's per square foot per year. The McAllen submarket is going through a decrease in rates. In the last 3 months, the median rate decreased $4 per sqft per year. That's a 16% decline in rent.
In the last 90 days, 15 listings have been posted online, which means leases might be going fast. You'll want to be prepared to make an offer immediately. There aren't many listings below 2,000 square feet available, 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 buildings in this area are around 1 stories. Most buildings in this region were built in 2002 and are Class B.