In case you hadn't noticed, the Wii U was released in America yesterday and supply shortages are leading to sky-high prices online.
eBay has seen Premium edition consoles, which have a US RRP of $350, sell for prices between $399.99 and $510.00. $480 seems to be the standard price for the high-end SKU.
Even retailers such as Amazon have hiked prices well past their RRP. It is currently charging $480 for the Premium bundle and $380 for the Basic.
With the console launching in Europe on November 30th and in Japan shortly after that, it's very likely that shortages of the console will continue all the way up to Christmas.