LOOT.Farm

LOOT.Farm is an automatic skin trade service.
On LOOT.Farm you are trading with bots, benefits from this type of trading are that you can sell you items intantly. Prices to every skin LOOT.Fram accepted you can on their pricelist.
Advantages
Interface
On LOOT.Farm very nice and clean interface
Commission
LOOT.Fram has 3% commission if you add loot.farm to your nickname, that's on of the lowest commission you can find.
Random cashback

Auction
In an auction you can find skins with rare stickers and floats, also if someone will overpay for your skin on auction you will get 95% of price skin sold.
Disadvatages
skins prices can change at any time
Money can't be withdrawable
So, if you wanna trade with bots you can consider LOOT.Farm as one of the best choices.
Dmarket

Dmarket is skin marketplace where you can sell and buy skins with reall people.
Advantages
Interface
On Dmarket modern and cool interface
Commission
Dmarket has 5% commission on selling skins, that's on of the lowest commission you can find.
prices
Dmarket has one of the lowest prices on skins you can find, average prices 50% lower than steam prices.
Targets
On Dmarket you can set the price you wanna pay for skin and if seller agree with your price you will get your skin.

Disadvatages
Dmarket not large marketplace and you can barely find there AWP | Dragon Lore or other high expensive skins
So, if you wanna get skins for low prices Dmarket might be the best choice for you.
Bitskins

Bitskins is skin marketplace where you can sell and buy skins with reall people.
Advantages
Prices
Bitskins has one of the lowest prices on skins you can find, average prices 50% lower than steam prices
Targets
On BitSkins you can set the price you wanna pay for skin and if seller agree with your price you will get your skin
Disadvatages
For new users Bitskins has high commission 5-10%
So, if you wanna get skins for low prices Bitskins might be the best choice for you.
CS.Money

CS.Money is skin marketplace where you can sell and buy skins with reall people and bots either.
Advantages
Overpay for skickers, floats and patterns
If you have skins with rare skickers, floats or patterns, you can get really good overpay on Cs.money for them.
Size
CS.money one of the largest trading website. You can find almost every skin with rare stickers, floats and patterns.
Disadvatages
Cs.money has hight commissions that can be up to 20% depending on skin popularity, the higher popularity the higher commission
Money can't be withdrawable
So, if you wanna buy or sell skins with rare stickers, floats or patterns CS.Money is good a great option.
Buff

buff is skin marketplace where you can sell and buy skins with reall people.
Advantages
Size
buff probably the bigest trading website where you can find all skins in large scale

P2P trade
usually tranding websites works with bots, this means that you firstly send your skin to a bot and then bot send your skin to a buyer, this method takes extra 7 days tradelock on bot. buff is using P2P trade, that meams that you send your skin to a buyer without bots and extra 7 days locks.
Targets
On Buff you can set the price you wanna pay for skin and if seller agree with your price you will get your skin
Commission
Buff has 2.5% commission, that's the lowest commission on marketplaces.
Disadvatages
I can be hard to withdraw your money if you aren't from China.
Buff can be a great option for buying or selling every skins you want.