Nintendo has so far refused to stick a price on the Wii Mini — which is coming to the UK on March 22nd — which means it's up to retailers to come up with a figure.
Amazon UK initially went with the rather obscure amount of £103.56, while rival online store ShopTo picked £84.85, which is apparently a "reduction" from £99.99. Amazon UK has since dropped to a more reasonable £79.99.
While it's nice to see a little bit of competition resulting in a better deal for consumers, compare those figures to the cost of an original Wii console and they make less sense. Amazon UK is currently selling the original model for £83.99 brand new, which means for an additional £4 you get WiFi, which grants access to online gaming, as well as Virtual Console and WiiWare titles. Second hand, Wii consoles are available for as little as £40 in some UK stores.