Originally Posted by
newyorkgeorge
Take the downtown E train (subway) from 42nd/Port Authority to 34th St/Penn Station ($2 one way on subway). Take NJ Transit from Penn Station to EWR stop (stop right after Newark). $14 one way for NJ Transit. Only other option would be the bus out of Port Authority (don't know really much about) but other posters might be able to give you information.
You can take the bus from the Port Authority to EWR for $14. That might be the easy way to go considering price is the same.