Most listings are in the $30's per square foot per year. The Gilbert submarket is going through a a boost in rates. In the last 3 months, the median rate went up $6 per sqft per year. That's a 21% rise in rent.
Compared to the rest of the Phoenix Metropolitan Area market, the Gilbert submarket has more expensive rates, and you'll have to negotiate above asking rent to be in this hot region.
In the last 90 days, 38 listings have been made available, which means new availabilities most likley are leasing quickly. You'll want to be prepared to make an offer immediately. About 3% of the available leases in the Gilbert are subleases, so you will probably have to focus your search on direct office leases. 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 1,700 sqft. Most buildings in this area are close to 1 floors. Most buildings in this region were built in 2006 and are Class B.