You should register on cex.io and you will see that selling btc price is much lower. For example, right now btc price in usd on cex.io is $2585, but if you want to sell btc inside this exchanger, the rate is $2392 for 1 btc...
you made me go an log in to my CEX.io account after a year or so
here is a screenshot of the market at https://cex.io/trade
you can see that when you sell you sell to 2600ish price, so i guess you were looking in a wrong place that you saw $2392
