Most listings are in the $10's per square foot per year. The Mesa submarket is going through a decrease in rates. In the last 3 months, the median rate decreased $1 per sqft per year. That's a 7% decline in rent.
Compared to the rest of the Phoenix Metropolitan Area market, the Mesa region has less expensive rates, so you should have no trouble finding a great deal in this undervalued region.
In the last 90 days, 186 listings have been listed, so you'll want to check back regularly for new listings. About 1% of the available space in the Mesa are subleases, so you will probably have to consider a longer term lease. 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 1,710 sqft. Most buildings in this region are approximately 1 stories. Most buildings in this region were built in 1990 and are Class B.