The same will most likely happen to a certain game in closed beta ATM (paying real $ for in-game consumable equipment!?! Yeah, right!).
I assume you are referring to Dust514? If that's the case, then it's not TOTALLY pay to win. Yes, you can get a bit of a shortcut by paying cash to buy better equipment a little quicker, but everything in the game can also be unlocked or bought with in-game currency that is earned through playing the game. Ultimately, those that pay 1) support the game developers with the funds to continue working on game and server upgrades and 2) will only see a temporary advantage.
There are a handful of items that can only be purchased with real cash, but they are only cosmetic items.
I completely understand the financial aspect of it. And if used properly, you can get a huge player base: teens with lots of free time and little cash can grind their way to good equipment, and people with jobs and not so much free time can pay for good equipment (as long as the total amount doesn't go over what a retail game + dlc would cost).
I'm just saying, if you want people to pay via microtransactions, make sure they have fun to begin with. Being a canon fodder is definately not something a lot of people consider fun.
That being said the whole pricing structure in the gaming industry is out of whack. Take Far Cry 3, for example, three weeks after launch and it's now 40$ at Target. Then developpers start wondering why people wait for price drops.
how is it pay to win... you can use everything..
In the free 2 play for Starhawk, not being able to build the powerful vehicles (I'm assuming you mean not just bulding the structure, but also not spawing the vehicle from the control panel), would, IMO, essentially amount to pay 2 win. You would be dependent on people spawing one for you. While playing with forums members and while using a mic, you would not have such problem as the people here will help out their team mates, playing with, often mic-less, randoms would be a completely different matter. In such case, good luck getting someone to spawn one for you, you'd have to rely on someone being foolish enough to leave an unmaned vehicle inside your / their base. That difficult acces to the vehicles, means you would have difficulty just getting good with them (especially the hawk).
With only the Sidewinder and troops weapons, as you suggested, you could still be somewhat efficient against ground pounders (provided there are no bubble shielded turret farms), however in any servers with hawks, you'd be hawk fodder. It's that difficult access to using and getting good with the game's supreme weapon (the Hawk) that makes me say it would be pay to win.
Also, not leveling up means you cannot have acces to the essential skills you need if you want to be competitive (TJ, EM, FM, Grinder).