Reference: Mabinogi. In the normal course of the market, you might find a particular item like a "Leather Long Bow" on sale for 100k. That would be a "high end price" for a weapon that was already fully upgraded. Then there were certain sources of special colors, a pink one that was only given during an event, or a red one that drops extremely rarely from certain mobs. With the same upgrades, these would sell 2mil+ in some cases. Same weapon - even a worse stat weapon - with a unique color would sell for boatloads. Similarly, the game has a dye shop, where you can change the colors of your clothing, and those sell for fortunes.
Being unique is something people will spend money on, in real life and in games. Mabinogi offers virtually no "pay to win" involved - people will argue that but the main buff cash shop items are things like "2x exp 1hr potion" and similar. The main intake of money for Mabinogi is dyes (for unique characters), pets (for convenience), and monthly subscription (mainly for inventory, because it uses this inventory-tetris style that limits bag size). You cannot really buy power. You can buy exp buffs if you're willing to spend a lot, but at the core of it you're still going to be playing the game to utilize that power, nothing is handed to you.
That, I believe, is what it comes down to for proper microtransactions. Mabinogi offers colors. Others offer "quicker game" buffs. If someone is earning 50% more exp than you, then they'll progress faster, but they won't reach a different end than you will. Likewise, if someone headshots you with a black rifle, you're just as dead as if they'd been using a blue rifle. I think a game like Planetside 2 will also feature some amount of teleporting for pay. Sort of, "free players warp after 10 seconds, premium can warp immediately" deal. This gets a little annoying, because that's an arbitrary restriction where the company sells you the disease along with the cure, but that can be allowed once you realize that the games need a way to make money somehow, and a 10 second wait is the least of your concerns.
On one microtransaction game, the cash shop features "cards" that you can buy. These cards have a direct impact on gameplay, like "+30% stone gathering speed" or "Immediately add 800 wood to stockpiles". This is how you directly buy power, and this is what I think Planetside 2 will avoid.
TL;DR - Planetside 2 may allow you to buy convenience or buy uniquely-styled gear, but I don't think you can buy victory. Still, we'll have to see what the actual game features, I'm just speculating.