Where/How to sell Skins fast and profitable?

Seriously, don't try to do anything fast...... Relax & take it easy with what you won, else you will get up scammed in the end.
You will loose profit even if you sell for real cash there is none paying 100% market price in real money, you will most likely end up 75% value at max depending on the knife.

Make a thread here and see if anyone wants to buy it for that price you want, make sure they're trustworthy by checking their reputation(the higher the reputation the better chance they're trustworthy) but also be cautious for frauds. If you manage to sell it for Paypal for $50 you can buy 25 TF2/CS:GO keys at $2 and then sell them for $2.2 in the market and you get extra $5. This was just an example, the price you want to sell foris yours to pick(some people sell keys for paypal at $1.8 as well).

If you sell it for $70 Paypal and buy keys for $1.8 you get 39 keys, selling them back in the market for $2.2 gives you $83 which is a $13 profit.

If I were you, I'd try to trade it for keys. With a bit of luck there may be someone that will overpay or at least pay for most of it's price.
After that I'd sell the keys on OPSkins.

That's my 2 cents :D

Yes I am trying to find someone atm :D