The Negev is CS2's $1,700 machine gun. Hold the trigger for two seconds and it becomes a laser. Nobody buys it seriously, but it has a skin that costs $2,462.
That skin is Mjölnir, a Mil-Spec from the Norse Collection, and it costs more than a Butterfly Knife Marble Fade. The Negev has 25 skins total, and two of them are worth more than most knife collections. This page lists every Negev skin with current prices.
Everything else is under $3: Ultralight, Bratatat, Prototype, Dev Texture, Drop Me, Wall Bang, Dazzle, Man-o'-war, Terrain, Nuclear Waste, Army Sheen. Most cost pennies.
If you buy the Negev in-game (ever), a Loudmouth at $1 or Power Loader at $1 is fine. Infrastructure at $11 is the most you should reasonably spend. The Mjölnir exists as a collector item and a conversation piece, not as a practical purchase. It is the kind of skin someone buys to screenshot for Reddit, not to use in a competitive match.
25. One Classified (Infrastructure). No Coverts.
Mjölnir FN at ~$2,462. A Mil-Spec skin. From the Norse Collection.
The Norse Collection is extremely limited. It produces skins for many weapons, but so few copies exist that even low-rarity skins on unpopular weapons reach four figures. Mjölnir also has an appealing design (Thor's hammer), which adds collector demand on top of scarcity.
Army Sheen at $0.01.