Instant gaming is selling keys for Overwatch which you can redeem on Battle.net for $14.94 which is the lowest price compared to other similar sites which have higher fees.
The store has more than 500 000 reviews on Trustpilot, so I assume it's legit. At least it worked for me so far.
https://nz.trustpilot.com/review/instant-gaming.com
About the Game
Once players join up, they are put into two teams of six along with other players. Each player can choose from up to 30 characters (in the game, these are called heroes). The characters are excellent: individually rendered, complete with personality traits and physical quirks that are charming and individual. These quirks can include an attractive smile, a wayward lock of hair falling across their face at a certain point, and many other subtle but significant features.
Each is given a mission or series of missions which can include either defending or attacking strongholds and laboratories, or escorting cargo or payloads across the map, guarding valuables from attack.
Each successfully completed mission results in prizes for the successful team, and they are rewarded. Examples of prizes or rewards for completing missions are things like cosmetic skins and upgrades that make you look cool. Ability is not upgradable through these prizes, which are just for fun and add greatly to the individual vibe given off by each character.
Minimum Requirements
OS Win 7 64
CPU Core i3-540 3.06GHz / Phenom II X3 720
RAM 4 GB
GPU GeForce GTX 460 / Radeon HD 4850
HDD 5 GB
Recommended Requirements
OS Win 7 64
CPU Core i5-670 3.46GHz / Phenom II X4 900e
RAM 6 GB
GPU GeForce GTX 660 / Radeon HD 7950
HDD 5 GB
Also keep in mind that price is converted from euros. You may incur a foreign currency fee on this site since they don't charge in NZD.