The typical asking rate per listing is in the $20's per square foot per year. The Gilbert submarket is going through a an increase in rates. In the last 3 months, the median rate went up $1 per sqft per year. That's a 3% rise in rent.
Compared to the rest of the Phoenix Metropolitan Area market, the Gilbert region has less expensive rates, so you should have no trouble finding a great deal in this discounted region.
In the last 90 days, 38 listings have been listed, which means leases are probably going fast. You'll want to be prepared to tour spaces as quick as possible. About 5% of the office spaces in the Gilbert 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 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 1,480 sqft. Most properties in this market are close to 2 stories. Most buildings in this market were built in 2006 and are Class B.