Well Game stop doesn't give you cash they give you store credit and they really rip you off i would say they would probably give you less than $100 for the X box and about $40-50 DSI as for the game probably less than $20
So if your lucky they will give you about 150 or more in store credit for that
Well it depends on when you got your Elite. They made a newer Elite that is a little stronger but, I'd say overall $100 to $140 but, GameStop is known for ripping people off in trade-ins (that is how they make so much profit). DSi should get you atleast over $50 maybe $100 if your lucky. Red Dead is sure to give you atleast $30 (since My friend took his in and I bought it ). That should be good enough but, if not just take it to GameStop, let the workers inspect everything (the better shape the more value) and they will tell you.