you can buy DIYs from Rubiks.com which is in Canada or Cube4you or Huskeyomega (on ebay) or pay way to much in few different stores around here for non DIY Rubiks. I have ordered from the three above and have no problems other than 2-3 weeks wait from the Asian two. Rubiks.com got me my cubes in 4 days.
Our Walmart hasn't sold 25th anniversary cubes for years. Walmart sells standard cubes that say 25th anniversary on the package but those are not 25th anniversary cubes; 25th's have different label on the center sticker and much better at cutting corners