prices of major cloud mining today (GHS/BTC):
cex.io: 0.00155108
pbmining.com: 0.0014
bitmaintech.com (BITMAIN cloud mining): 0.0008988
There are more but not mentioned, it is clear who will be the leader.
BITMAIN takes things seriously, it is not a joker, your company is very solid and known worldwide.
I doubt a lot that pbmining or any other company will be able to compete with their prices and services, in fact no one can compete with chinese.
http://2.bp.blogspot.com/-KMPtQCfqNuw/VIFLnGZoa0I/AAAAAAAAANg/VGmGQPcoJRE/s1600/minar.png 
That's not Bitmain, that's a reseller market place. Bitmain itself charges 0.0001125/GH/s. That's not really that important a distinction though.
The biggest difference is that they charge a maintenance fee of $0.0022896/GHS/Day. At the current price, that's
BTC0.00018874/month.
that explains the difference in payments, otherwise would exist SKIMMING PAYOUTS.