I will be taking the train from the 30th Street Station in Philadelphia to EWR but on the Amtrak site I cannot tell what the fare type is.

I know it is not business class fare but I cannot tell if it's a discount fare or what. Does anyone know what the $50 fare class is out of Philly? I thought about just upgrading for $22 but having never been on the train I don't know the benefits.