Try the fish market along Jalan Pasar in KL for the smaller sized (less expensive) goldfishes, or if you're in the market for top grade BIG lionheads, try Cheras Aquariums. Fish can cost up to $800 for a big black lionhead of top grade.. but make sure they're healthy b4 making purchase. Many a times I've seen the fish at Cheras less than healthy... hope they do something about their inadequate filtration.

PS: wen will shrink if the fish is starved for long periods of time.