If it's available to be gained in-game, then it's not pay to win. In fact, it's just the opposite - someone who would buy that gear in the store instead of grind for it would have less game time and experience than the player who put the time in, thus, all else being equal, the player who put the time in would be more skilled than the buyer and thus still have the advantage.
A lot of players throw around the P2W card without having the faintest idea of what P2W really means. If you want an example, Google ZT Online. That is what Pay to Win is. As long as the Cash Shop does not offer one piece of gear with stats better than anything that can be gotten by playing the game, then no matter what gear it is, it is not P2W.
P2W occurs whenever
a player can circumvent an aspect of the game simply by paying money to do so.