It UK is similar to the US, you can post it for 1 day and get the same results. I would query ebay and see how much the average price is for a Wii with your similar accessories and games.
Then if you feel more comfortable put it for 3 days as a maximum. Make sure you are honest in your auction. If you know its in perfect condition then say so and offer a warranty for defects to make people feel all cozy.







