While the OP is trying to get to NJ, for those needing to go between Boston & Manhattan, I would recommend the LimoLiner. It's $160 RT or $89 one way. It is far more comfortable than Greyhound, you have an on board attendant to serve you drinks and snacks, and there's free onboard internet.

I'm actually posting this from the bus right now. You can find more info at www.limoliner.com.

Until the Acela has onboard internet, I'll book the limo liner if it fits with my schedule. It also allows me to work & stay connected, which you don't have on a plane.

Of course, being a bus, it is susceptible to traffic delays. That is one thing the train has over the bus.