Prices on yobit are always higher than other exchanges, I don't know why exactly, maybe because few people use it.
Personally I didn't use it because of its high fees, I tryed once to use it to sell a token but I found that I have to pay more than 40$ to make a deposit which is more than what I am going to win from selling on it.
Variances are very common across exchanges, but it does partially reflect the exchange's willingness to buy your crypto from you, and also, as mentioned above, it factors in ease and speed of withdrawal - it is typically slower on Yobit for fiat withdrawals, although they do have the benefit (currently) of not suddenly blocking your withdrawal and requesting verification. Note that they have slightly higher withdrawal fees than others but they don't have country restrictions, and all-in-all, minus fees, you still get a little more if you sell to them.
And... there is no deposit fee on yobit, so not sure what you're talking about.
~snip
i heard that with a wallet such as block chain you can deposit and withdrawal with no fees on yobit i don't know if it's true or not i gonna try it
The wallet you use has nothing to do with exchanges fees. You pay your own fee if you deposit from blockchain wallet, as with most other wallets where you control private keys. Online web wallets tend to charge their own network fees. All exchanges will impose withdrawal fees. Only Localbitcoins as I know charges a deposit fee.