I can go get a silver aro here for about $30 at 5-6 inches and i can get a rtc for about $20 and no store will take them back over 16 inches. My friend got that much because our friend owns the store and he bought it for his show tank at home. I trade in my aro at 18 inches and got $50 trade and the store sold it for $80. RTC are worthless here if big and usually have to be given away.... If you plan on buying fish just to grow them and trade them in for credit then your wasting your time because most stores will stop taking fish from you.