It is under $200 last I heard it was around $180 or so but it's been awhile since I checked. Sell it to a CAG member or on ebay or something as you will definitely get lowballed on an item they will resell for $220 used.
Again, do not trade it to Gamestop. You can easily get a better deal else where.
What I would do is find out when a store (Target/BB) are getting a shipment (Sunday for ads that advertise it) and wait till they sell out and then wait for people to come in looking for one. Offer those people your used Wii. If its in working condition and includes everything (plus Virtual Console games if you have any) you could easily get someone to pay $220+ for it.