Compared to the rest of the DFW Metroplex market, the Allen submarket has higher rates, and you'll have to negotiate above asking rent to be in this hot submarket.
In the last 90 days, 19 listings have been listed, which means office spaces 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.
Even though the median size is 3,640 sqft, there are still 0 leases below 2,000 sqft. Most properties in this area are around 2 stories. Most buildings in this region were built in 2005 and are Class A.