I'm from Vietnam but right now I live in Texas, U.S. dat is really rare in here so I consider $60 for 4'' is a fair price! In Vietnam they can be wild caught so a 2-3'' ST usually go for $10-20!it depend on how much food you feed, what food you feed, maybe with right amount of food per day it can growth about 3" to 4" inch per year but after reached
around 12" inches it will slow down. By the way where u from and how much 1 piece for the so call ST in your area. Thanks.