Dry shampoo has become a necessity these days (when used sparingly). Grab a 3-pack of Batiste, your favorite dry shampoo, for only $16 when clip the $1 off coupon and sign up for Subscribe & Save (you can always cancel) and make sure you never have greasy roots again.
And if you need some that won’t show up white at your roots, the Blonde and Brown 3-packs are $19.