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.
so khaled what exchange you are using in the mean time ? and is there any with less fees than yobit ? what is according to you the most optimal exchange where fees are cheaper and you can find a lot of cryto currencies with their real values ?