Its only that price as its rare and enough people with money want it. What else are they going to spend it on, literally there are people with 5 Lamborghini in their drive way who are bidding on these items. Capture an audience like that and prices will always be silly, read about someone being charged £80 for 2 bottles of water in london somewhere
I can load this knife texture in game now, its actually free part of the game to anyone. The difference for this price is he can use it online in an official multiplayer gamer, where I will ejected from the game as I dont 'own' it.
You can probably play on a private server with friends multiplayer and not pay 200 for it. Some 'community' servers you just logon and type !knife to select what you want but it would be model only not textured. These are not official servers though, people are obsessed with rank on csgo hence a lot of aim hacks but the skin enforcement is perfect