I would say it is worth it. I am not a completest so I do not have every valk. But I still buy enough not to afford a Xbox 360 also. Waiting for price drop.
These are what I have that I have the 1/60 and same version in 1/48.
Roy S, Hikaru A, Hikaru J, Cannon Fodder, Max J, Millia J.
With the 1/48 Milla they color is nicer to me and you get all of the missiles. Of course the 1/48 are easier to make stand stright for me. I had issues with the wings on the 1/60 not holding the missiles. They would pop out from time to time. The backpacks lock on the 1/48 version better. So with fast packs they do not tend to fall back.
So I would say the Roy and Millia would be a good place to start.