We don't use square footage to price homes in this part of NJ. We rarely even show sq footage on the listing unless it is new construction.
We use similar, comparable sales to arrive at a market price..
As an agent, I would compare the overall size of the home, number of bedrooms and baths - basement or no basement (finished or unfinished)............ and number of updates (new baths and kitchen?, internal systems in of the house?)........etc........ part of the comparison also includes the lot size and location within the town (busy street or quiet?).
Call a local agent - they can do a market analysis for you.....for free!