I've got an 8:30PM leaving from JFK on a Friday night (4/15).

Our last stop on our vacation is the Edison museum in West Orange, which closes at 5pm. So we've got 2.5 hours to get to JFK. (So we get there an hour before the flight, it's domestic)

What's the fastest cheapest way to drive to JFK from Orange, NJ? And what's your best guess as to how long I should expect it to take at this time and on a Friday night? (And how much are the darn tolls???)

(I asked previously about train connections, but my wife will be almost 8 months pregnant and says she may not want to consider that option)

Thanks for the help!