Amanda, I'm glad you love yorkies and that you have done some research on them but in your research you should have come across the fact that there is no such thing as a "teacup" dog. It is just a marketing term used by unscrupulous breeders. I have a 2- 3 lb. dogs and they take more attention and care than my other dogs. If you have Crohns disease, I would suggest getting a little larger dog, like 5 lbs, which is still a small dog but would be less work for you. To find a Yorkie under $400 I would check
Petfinder.com: Adopt a pet and help an animal shelter rescue a puppy or kitten., you could find your new best friend there! Good Luck!!