[quote name='pfp']Do you know if they're going to stop gamecube anytime soon?[/quote]
This won't happen anytime soon due to the popularity of the Wii and full backwards compatibility.
In terms of refurb fees. I never, ever accept them. Sometimes it's just a matter of pushing back -- I've had them waive the fees by me just saying that I won't pay them and that I refuse the trade.
Once I traded in a few games and didn't know their value ahead of time. I saw on my receipt after we were done that there was around $5 in fees. I turned right around and demanded that they either refund that fee to me in full, or reverse the trade. They didn't bother to tell me about the charges and that pissed me off. They ended up adding the credit to my account.
Never accept their fees. If they try to charge you just refuse and take the game to another gamestop, or back to the same gamestop on a different day.