The typical asking rate per listing is in the $20's per square foot per year. The Philadelphia Metropolitan Area region 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% increase in rent.
In the last 90 days, 940 listings have been posted online, so you'll want to check back regularly for new listings. About 2% of the available leases in the Philadelphia Metropolitan Area are subleases, so you will probably have to consider a longer term lease. There aren't many listings below 2,000 square feet posted, so finding a space for a small business might be tough.
Even though the median size is 3,060 sqft, there are still 0 new availabilities below 2,000 sqft. Most properties in this area are around 2 stories. Most buildings in this area were built in 1982 and are Class A.