Why can't you buy cf constellation weapons?

You can buy it, but you should buy it according to the time corresponding to the constellation.

The 12 constellation weapon in CF mobile game is a collection of weapons in the whole constellation series, and all of them have been sold at present. 12 constellation weapons are provided free of charge from time to time in CF mobile games.

Cross the Fire Line (CF) was developed by Smile Gate in Korea, published by Neowiz in Korea and operated by Tencent in Chinese mainland. Crossing the line of fire is a first-person shooter online game, in which the player will become a mercenary and compete with other players. In 20 17, the number of registered players of crossfire reached 600 million.