There are far better uses for transit funding in the NYC area. Even within Penn Station, the low-hanging fruit would come by improving the track level (wider platforms/fewer tracks), rather than the concourses.
If this piques your interest, Levy's "Eliminate Penn Station" proposal[2] is worth a read, although he admits it's somewhat trollish.
[1] https://pedestrianobservations.wordpress.com/2013/05/31/quic... [2] https://pedestrianobservations.wordpress.com/2015/07/15/elim...