Butterfly Knife Marble Fade Factory New is a Covert CS:GO knife skin that was added to CS:GO as a part of the Take The Trip To The Canals Update on March 16th, 2017. The Butterfly Knife Marble Fade features the real-life inspired curved blade with a cutting edge on a single side and is painted with black and silver metallic paints and then canty coated with three different colors that blend seamlessly with each other.
The Butterfly Knife Marble Fade is only available in two exteriors, Factory New and Minimal Wear, and can be obtained from two different weapon cases, these being Spectrum Case and Spectrum 2 Case.
Due to it being one of the rarer skins out there, you shouldn't be surprised that the Butterfly Marble Fade Factory New comes with an extremely high price tag. If you wish to get your hands on one of these, you can expect to pay anywhere between $1300 and $1600 for the regular Factory New version.
If you don't want to sell skins but want to have some more expensive ones, you can trade CSGO skins for other ones.