Starfighters is a Bundle. It was released on December 20th, 2019 and was last available 174 days ago. It can be purchased from the Item Shop for 1,800 V-Bucks when listed.
How-to Get the Starfighters Bundle
Starfighters can be obtained with V-Bucks when it is in the Item Shop. Cosmetics rotate in and out of the shop each day, so we have no way of knowing when it will return.
Attachments are items that come with a cosmetic when it is obtained.