The only difference is that with GTA V $60 will get you the full-game experience.
With Evolve, they sell you the game for $60, but not before they ripped out half the content from it so that they can sell it to you separately.
EDIT:
The Behemoth will be available for purchase this spring for $14.99
The four playable Hunter characters will be available for purchase individually for $7.49 each.
That's only an example of $45 of content cut out from the base game to be sold separately.