I have read the FAQ on the "free-to-play" model for this game:
While Petroglyph has promised not to add items that are exclusive to whales, it is still allowing players to purchase items that are available to free-loaders (that's what players are if they are not paying a single thing) too but with real money.
If the game has expendable items such as ammunition, wouldn't this mean that paying players will get to be able to shore up their logistics more easily than freeloaders? They won't have to worry about running out of supplies and the in-game currency to purchase them if they can just fork over Trion dollars to stock up.
P.S. You may have noticed that phrase "whales". In case you are wondering what it means, you might want to read these:
If you can see this, I am posting from GameFAQs. If you can't see this, I am posting from GameSpot. Go figure.