The price of a Border Terrier can be all over the place, depending on how old they are, their pedigree, and where they're from. You're looking at shelling out between $2000 to $4000 AUD for a top-notch pup from a breeder who really knows their stuff.
List of Border Terrier breeders in Australia
Border Terrier, Near Temora NSW
Border Terrier, Blackmans Point, Mid North Coast NSW