Don't be sucked into thinking, "Oh, the stuff on eBay is WAY cheaper than in the stores!".
Get out of the house and look around people...
Some sellers are selling the default Nintendo Wii system (with the default included 5 Wii Sports games) for way over the RRP AU$400.
Do some research and compare the value for money before you buy.
Don't just go off sellers saying that all stores are sold out. If you're patient enough you can save yourself hundreds of dollars!
I just wrote this guide because I went to Electronics Boutique just then and they are selling their systems for $399!