Here is a list of websites i have found that sell cubes (and other twisty puzzles) for good prices.
-lightake: sells puzzles and other things (toys and gadgets).
-v-cubes: sells lots of different kinds of V cubes.
-HK now store: sells all kinds of twisty puzzles, cube lubes, and stickers.
-The Cubicle: sells puzzles, lubes, and stickers.
-Mefferts: sells lots of interesting puzzles (e.g. gear, barrel , shape mods)
-WitEden: sells Wit-Eden cubes, and a few other brands.
-Speed Cube Shop: sell cubes, lubes, and stickers.
-SpeedCube AU: sells good cubes at good prices also sells stickers, lubes, and timers.