On average, listings lease in the $10's per square foot per year. The Casa Grande region is going through a a boost in rates. In the last 3 months, the median rate went up $18 per sqft per year.
Compared to the rest of the Phoenix Metropolitan Area market, the Casa Grande region has lower rates, so you should have no trouble finding a great deal in this undervalued region.
In the last 90 days, 6 listings have been listed, which means listings are probably leasing quickly. You'll want to be prepared to tour spaces as quick as possible. 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 2,030 sqft. Most properties in this market are close to 1 floors. Most buildings in this region were built in 2003 and are Class B.