Standard Edition should've remained free, it's clearly not worth the money despite how enjoyable it may seem at first, once you finish the extremely short campaign and few scattered loot missions you will then realize how short lack luster the game is along with the level 20 cap, and how you need to buy the expansions to get the actual "FULL" game. Also some of the main game was tied to the expansions despite originally being available to the base game before the expansions came out.
J_P-'s comments