Most listings are in the $20's per square foot per year. The Surprise submarket is going through a decrease in rates. In the last 3 months, the median rate decreased $10 per sqft per year. That's a 32% decline in rent.
Compared to the rest of the Phoenix Metropolitan Area market, the Surprise submarket has lower rates, so you should have no trouble finding a great deal in this depreciated region.
In the last 90 days, 6 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 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 1,100 sqft. Most properties in this market are approximately 2 stories. Most buildings in this region were built in 2006 and are Class B.