Where to buy a wii from?

I am going to buy a wii but I don't know whether I should buy it preowned. I am wondering whether to buy one preowned from ebay or game so i will save �15 and a get a game or two with it or to buy brand new as argos does a deal and has some in stock at the moment. Buying brand new means I can have it straight away and have proof of purchase but have spend a little extra. Would you prefer to save a little or spend a little more for peace of mind and to get the item quickly? I would greatly appreciate your answers,