Thats pretty much what im wondering.

Assuming that the GH associated with your account is your own, then what you earn from them mining is less than the value the GH has dropped in that time.

185GH mined for 14 days gave 1.00xx btc

Dec 10th - Opened at 0.0734/GH, value = 13.579
Dec 24th - Opened at 0.0628/GH, value = 11.618 + 1btc mined

So in 2 weeks its gone from 13.58 to 12.62btc, a total of approx 15btc has been put in there since mid Oct, all funds being reinvested into GH until Dec 10th.
So that 15btc and all the funds CEX mined, has given 12.6btc all-in if cashed out today.

Theres just no logic to the pricing on there, while the likes of ebay has seen hardware prices double because of the BTC/USD rise, and conversely the network difficulty goes up 20-30% every 10 days, the CEX price doesnt give a hoot, its in a little universe of its own. Im convinced the only people who are making money are CEX and those who've whored themselves out on forums plastering referral codes and so-on and havent got a cent of their own money in there.