I picked up Umberto at Target for $9.99 (I believe) and it comes in a decent sized can (4 oz). I apply it by sectioning off my hair into four parts - left side, middle, right side, and back (where my crown is) and spray each section holding the can about 6 inches away from my head. It goes on white, but once you rub it in (I do it with my hands AND brush), it immediately gives your hair volume and soaks up all the grease. However, the white residue doesn't completely go away. I'm lucky enough where my hair is fairly light, so the dry shampoo just makes it look a bit more blonde on top. I don't know how well this spray would work on darker-haired people.
Here is a picture of my hair at 8:00pm (13 hours after using dry shampoo, 48 hours since the last time it's been washed) - I know, gross! But I promise, this is a HUGE time saver for those of us who are not morning people... plus I hear it's bad to wash your hair every day, so that's my excuse. Let me know what Dry Shampoo you love and I'll check it out!
(It was no make-up day) hehe!