I came up from DC to see a soccer match at MetLife in June. I stayed at a Holiday Inn on the south side of Newark Airport. It was $175 per night, which was great for a single person.
I took NJ Transit to and from the game, which was incredibly convenient. Except for going back to the hotel from the game because it took 45 min for my specific train line to arrive. Secaucus Junction serves all NJT lines so it takes a lot longer to get home than you think. Also, my hotel was not necessarily pedestrian convenient to NJT despite what Google Maps said, but I did make it work. It is nuts how the pedestrian access from the N. Elizabeth and Elizabeth NJT stations near EWR is so bad. Six lane roads everywhere.