You should be able to get one fairly cheap. The only thing I'd advise is to set up a spy camera for at least the first several weeks to know exactly how they treat your baby. If you see what you like keep the nanny, and even give them a raise. 

well,where do you live? in zhejiang province, the pay is high, for chinese ,RMB4800 if the

 grandmothers live with us,and RMB 2500 depends she does not live with us.

But,for foreighers.this may gets higher,because, the grandmothers must speak english and educated, you know,and you can ask some 中介where we also find babysisters and grandmothers there.

actually i found mine in jollybeijing. 5000 a month. Quite happy with her. Before was thinking looking for a Filipino. 

If your are not interested in or willing to bring up your own children,why have a child.They are not pets.

When my wife first had our twin boys, we had 2 live-in helpers, one to take care of the day-to-day house work and the other was a teacher we hired from an agency who's job was just to care for the boys.

The one we hired to help care for the boys was fantastic (except for having a voice that sounded like Minnie Mouse on helium).  She had a degree in law, spoke basic English and was absolutely wonderful with our boys.  We paid her about 3,500 RMB per month.  She stayed with us for 2 years and still comes by to visit the boys (3 years later) every now and then.

The other maid works 7 days a weeks and gets paid (then) 3,000 RMB per month.  She has been with us for almost 6 years and is basically a part of the family.