Welcome to Bird Board! I do not have much experience with grass parakeets but if you are thinking of getting them I would post in the section. There are many experienced people in that section. If you want to buy from a breeder I would check
BirdBreeders.com - Bird Breeders Directory of Availability and Parrot Breeders . This is a great site that lists many reputable breeders. Many of these breeders have been rated by customers and you can read their reviews. Good luck and enjoy the site!
Matt