Volumizing shampoo and conditioner

I'm looking for a good, inexpensive volumizing shampoo and conditioner. I checked out the sally's web site and they offer quite a few but, I'm not sure which ones work the best. Any recomendations would be helpful. It dosen't have to be from Sally's, I just don't want to spend too much on the brands sold in salons.

I like the ones you can buy in the grocery store by Dove and Suave (they have specialized lines now for volumizing and fine hair). I used to spend tons of money on salon products but I can't tell any difference and actually some of the salon products made my hair greasy.