I bought a knife (worth about £450) a month ago from bitskins, partly because it's a cool thing to have and look at, but also because it makes me play better. I'll sell it on bitskins when I stop playing csgo for a while, or if I need the money.

Good thing about bitskins is that it's cheaper to buy items compared to the steam community market (of course this means you have to sell it for less), but you can also get real money when you sell it, rather than it going into your steam balance.

So that's what I'm doing. I'm not worried about the price falling by a significant amount.

If you're worried about wasting your money, maybe sell the knife and congratulations: you made profit.