The Station would require a massive underground footprint which could easily add another billion to the project and you have to retrofit the old tunnels to support a station as these tunnels will be one way...I just saw on Jersey Digs that there will be a meeting this Thursday in Union City to discuss the Tunnel project; however, according to the map below, there are no plans to include new stations. Personally, I think this is an outrage considering that this is a once-in-a-century opportunity and the marginal cost to build stations in Union City and uptown Hoboken is negligible compared to the overall cost of the project. I'm tempted to show up if I can fit it into my schedule.
I also find it ridiculous that the eastern terminus for the project is the same spot where all the existing tunnels end - Penn Station - and not a critical location that's currently less accessible from NJ such as Times Square or the 57th Street area.
Altogether this project (and the former ARC Tunnel) seems so short-sighted.
Current preferred scheme: http://hudsontunnelproject.com/documents/2017-04-05_Preferred_Alternative_Figure..pdf