Welcome to YorkieTalk, boquanzhu! A lot of the questions you asked are found in our FAQ at the link below:
http://yorkietalk.com/forums/showthread.php?t=6016
Personally, I would think you'd get a better price in Texas rather than NY for a smaller-sized Yorkie (there are no such things as teacup Yorkies). But do beware that there may be additional problems with their health due to the smaller size than a standard 4 to 7 pound Yorkie. Good luck on finding a new Yorkie!