You can get a well-bred GSD from a good breeder for about $1500 (maybe a bit less). Read through that link I posted, research the lines and determine which will best fit with your goals of having a dog. Then, find a breeder that will match those goals. It will be worth your time and money to find a good breeder who does health checks on the parents (hips, elbows, DM, etc) and titles and/or works the dogs (give you an idea on the dog's temperament).
ADCH Mikko (USDAA) SCH-B; (NADAC) EAC, EJC, TN-E, TG-E, VerO; (AKC) NAJ, CGC; (NACSW) NW1 - 9 year old GSD