It depends, around the holidays $250-$600. Normally if they are used you can get one for $50-$150. But without an occasion $250. They can be good prices. But if I were getting one and had tots or infants keep away because they can go "BOOM!"
You can get a Wii online for a good price at eBay. Sometimes at Amazon. You should compare prices online. Check classiefied adds and penny auctions, too.
You Will need A sensor bar to play wii You Get it when you buy a wii but if it gets ruined you can get one for a good price on www.ebay.com
get a PC because it have a good games for lower price
They can range from $5 to $14.99 depending on what retailer you are going through.
about $249.99
costco has a good standard price, any better than that will have to be a sale.
$279.99
The closest you will get to retail at the moment is to check out this guys advice on where to buy a wii in stock for Nintendo Wii price and not the post xmas price. http://wheretobuyawii.tumblr.com/
No you can trade in a Nintendo Wii towards the purchase price at a Gamestop or similar store, but you may get less than half of there selling price for the Wii.
GameStop
It all depends on the price of the xbox 360 and the price of the wii. I am pretty sure that they will let you though.
A Nintendo Wii system costs approximately $250. The price varies from store to store so it is a good idea to check the prices before making a purchase.