Most listings are in the $20's per square foot per year. The River Place region is going through a decline in rates. In the last 3 months, the median rate fell $1 per sqft per year. That's a 5% decrease in rent.
In the last 90 days, 1 listings have come on the market, which means leases most likley are leasing quickly. You'll want to be prepared to make an offer immediately. 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 720 sqft.
Public administration is the dominant industry in this region. Most of the occupants of River Place work from home. Commuting more than an hour and a half a day is the norm for those who opt to reside in this part of town.