The typical asking rate per listing is in the $10's per square foot per year. The South Philadelphia submarket is going through a a boost in rates. In the last 3 months, the median rate rose $20 per sqft per year.
Compared to the rest of the Philadelphia market, the South Philadelphia region has lower rates, so you should have no trouble finding a great deal in this discounted submarket.
In the last 90 days, 7 listings have come on the market, which means listings most likley are going fast. You'll want to be prepared to tour spaces as quick as possible. There aren't many listings below 2,000 square feet available, so finding a space for a small business might be tough.
Even though the median size is 6,490 sqft, there are still 0 listings below 2,000 sqft. Most buildings in this area are close to 4 floors. Most buildings in this area were built in 1930 and are Class B.