The difference in price come from the skin an equipement has. Which means you can buy an exotic weapon for 1 gold that would have the exact same stats as another exotic that cost 300 gold. This come from the fact that stats on gear don't have random values but fixed values. You can indeed use real money to get in game gold, however the gear you can aquire with this gold has the same stats than lower priced gear with the same rarity. TL DR : Guild Wars 2 isn't pay to win but pay to look pretty. It's also important to note that all players' stats are equalized for sPvP, regardless of level or gear. Living World Season 2 is required to get ascended trinkets with Nomad's or Sinister stats.
The digital deluxe upgrade is the only way to unlock the Mistfire Wolf elite skill, which is only useable in PvE and WvW.Costume brawl is generally silly and unbalanced, even without considering gem store items, so this isn't really a "competitive" advantage. Some toys can be used for costume brawl, and are often more powerful than costume brawl transformations obtained through other means.These can only be used in PvE and WvW, and are non-problematic in WvW due to its large-scale, casual nature. Some boosters that are obtainable from Black Lion Chests can give increased running speed, attack strength, regeneration, or armor for one hour.There are a few "competitive" advantages to be gained, but these are minor, and none affect sPvP: Other items also exist, such as keys to get random items, items that increase durations of nourishments, and toys.These include items such as ones that bestow random transformations, make everyone appear to be a bobble-head, allow you to start a water balloon fight, or provide additional dance moves, and also musical instruments. Amusement items can have interesting effects on the player and others.The digital deluxe upgrade and living-story unlocks (for ones that you missed getting for free) are also included. These include additional character slots, bank space, inventory bag slots, or crafting licenses. These include infinite-use gathering tools, instant bank access, a home instance teleporter, reward boosters, and revive orbs (usable only in PvE). Convenience items allow players to do things in a faster or more convenient way.These include things like such as weapon or armor skins, outfits, finishers, mail carriers, makeover kits, dye packs, or miniatures. Cosmetic items only affect appearances.Items offered in the Gem Store fit into one of the following categories: Since in-game gold can be traded for gems, this means that anything you can get from buying gems with real-world money can also be bought by converting in-game gold to gems. Gems are obtained through real-world money purchases, trading in-game gold, and obtaining significant numbers of achievement points. Expensive items are typically those with the rarest and most sought-after appearances. This would be problematic in games where having the highest stats is rare, but achieving the best stats in the game is common in GW2, even among casual players. This means that anything that can be bought using only in-game gold can essentially be bought using real-world money. Gems can be traded for gold or spent in the Gem Store. Microtransactions in GW2 are made with an in-game currency called Gems.