Unfortunately there aren't at all. It's essentially a big stadium with not much around it apart from a training facility. Granted, the Americans sell alcohol in their stadiums, by memory the cheapest pint was Miller Lite at circa $9. Most pints in stadium retail $10-14.
Your best bet is to have a carry out, have some tins on the train out there and then join a tailgate party when you get to the 'parking lot'. Everyone is pretty welcoming. Just don't make Trump jokes - I learned the hard way ha ha.
Also mate, this goes for you and anyone else interested, if you want great views of NYC, head for Top of the Rock at the Rockefeller centre. Most people associate the Empire State with the best views when in fact, Top of the Rock is better. That being said, it costs roughly $30-40 to go up to the observatory tower.
Here's a trick: go to Rockefeller plaza and ask to be shown to the elevators to the Rainbow Room. It's a bar/restaurant about 3 floors down from the observatory and it costs nothing to go up to. Once you get up there, you can get a pint of beer for about $14. Not cheap, but you save yourself some cash with pretty much the same views. Even if you go up and get a Diet Coke at $5, you are still making quite a saving.