Thank you grindian. I have read the link and I think it is a great help.
I have received MEng@Cornell with 10000$ scholarship, MS@UCLA, MS@Yale, MS@Columbia, and some other school like Chicago, Dartmouth but not on the same level.
I think the peer school should be Cornell here.
One more thing, who should I write negotiation letter to? The article in the link said write to admission officer. Should I write to the dean or the secretary?
Thank you again for answering!