This powder retails for $19US on the Sephora website, there is also a Hydrate and Brighten brush that is meant to be used in conjunction with this product, which sells for another $30. I will let you in on a little secret though, I bought mine off Bridgette's Boutique for only $13.50 it's an online beauty discount store, she also has the brush up for $9.50 (I am thinking of getting it too). You can use any brush with this, I would suggest a fluffy powder brush so that you don't apply too much.
However, as I mentioned above, I was disappointed in this product because I felt zero cooling or hydrating qualities to this, please let me know below if you did. I realize it wasn't going to be a sort of wet-dry feel like with the Almay Hydrating Makeup (which I love), or similar to the Prescriptives Liquid Powder (which I am lemming). If anyone knows where I can find the Prescriptives powder for cheaper, please let me know. But aside from being light on the skin and pretty in the package, I don't see what this actually does, maybe I am missing something.
Have you tried the Bare Escentuals Hydrating Mineral Veil?