Most listings are in the $20's per square foot per year. The Tempe region is seeing a decline in rates. In the last 3 months, the median rate fell $3 per sqft per year. That's a 11% decline in rent.
Compared to the rest of the Phoenix Metropolitan Area market, the Tempe submarket has greater rates, and you'll have to negotiate above asking rent to be in this hot region.
In the last 90 days, 159 listings have been listed, so you'll want to check back regularly for new listings. About 6% of the listings in the Tempe are subleases, so you will probably need to sign a longer term lease with the landlord directly. 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 2,350 sqft. Most properties in this area are approximately 2 stories. Most buildings in this region were built in 1987 and are Class B.