Driving to PATH in Harrison will cost you $10 to park, plus $3.50 for PATH, plus car expenses (50 miles), plus a subway ride if you're not working within walking distance.
It appears there's a bus run by trans-bridge
Trans-Bridge Lines, $40 plus $4.50 subway from Port Authority, round trip. It goes down to $26.75 for the bus part if you get a commuter book.
NJT from White House is $29.50, plus $4.50 subway from Penn Station, plus car expenses, but parking is free (though I have no idea if it is available). Slightly cheaper for a weekly pass.
I don't know what your car expenses are but I suspect these options are all fairly similar, with PATH having an edge. You can bring it down a bit more by going to a cheaper lot in Harrison; the $10 is for 12 hours in the garage next to the station, but there are cheaper lots around.
Whether you can actually do it in under 2 hours is another question.