Its not region free so you have to get US ones in US, UK ones in UK etc. so BE CAREFUL.
It's because all of the points are different prices in different countries.
Look it up on wikipedia
Pricing
A 2,000-point Wii Points card is available in the USA for around US$20, or for €20 in Europe and £14.99 in the UK[5]. Wii Points can be bought from retailers or purchased online directly from Nintendo. When converting from Wii Points to American dollars, 100 Wii Points equals one dollar. Reggie Fils-Aime has stated that 2,000 Wii Points will cost about $24.99 Canadian[6]. Pricing was also given for Wii points in Japan, with 1,000 points being exactly equivalent to ¥1,000 ($8.46)[7]. Prepaid cards in Japan will be made available in multiples of 1,000, 3,000 and 5,000 points, with the 5,000 point card coming bundled with a classic controller[8]. In all other regions, there will only be 2,000 point cards, at least initially. For example, in Australia you can buy a 2000 point card at retail for $30AUD or you can purchase through your Wii with a credit card 1000 points for $15AUD, 3000 points for $45AUD or 5000 points for $75AUD. Wii Points cards are region-specific and are not transferrable to different regions