QUOTE (Mr Kilsyth @ Sep 8 2008, 00:19)

I would say Gamestation if you are looking to trade stuff in. Wont be beaten on trade ins apparently.
You are the most naive person that has ever existed.
You may have given the worst advice in the history of time.
Sell the PSP on Amazon (or Play, depending which has the higher lowest current selling price), which each game individually. There's a good chance you will get quite a large percentage of the money towards your Nintendo Wii.
I use Play most of the time now, it's actually a lot better than Amazon, but I don't tend to sell kids toys.
I've had a look for you... a nearly new PSP is currently sitting at £79 with no games. Add the games on individually and you've got your Wii, as you can use the money as Playtrade cash, so it's far safer than eBay.
EDIT: BTW A Wii with Wii Sports is going for £140 nearly new on Play, so it seems you could get your Wii with money left over after selling the PSP and games.