I look at how hard it is to stay 90 day just in LEO on the ISS and knowing that it is quite an effort how can we do this with out setting up some sort of base structure on the lunar surface.
The tonage of supplies would mean one ship by its self, another for crew living quarters, and more if equipment(may mean mining) to build a subterainium area for living in a protested environment is implimented, and more...

The trip to the moon may cost Nasa some other project was partly an interview with a former Nasa Manager Kieth Cowing a space expert and Nasawatch (plus others) web site with the inside scoop.
Depending on the design of the rockets to come there may be instellation closings or redirecting of work from one site to another as he indicates in this write up.