A Day Trip to New York City [closed]

So, let's say I want to go to New York City to see a Broadway show and head back home immediately after. Say I live relatively equidistant from both Baltimore, MD and Washington DC, and BWI isn't too far either (for example, in Columbia, MD or Elkridge, MD). If I have access to a car, and am perfectly willing to walk some distance, take metro/train, or a bus (but no planes, you know how crazy those prices can be). What would the most feasible option for making the trip to and fro without breaking the bank?