So I've always bought drug store shampoo and conditioners and I don't want to spend crazy amounts of money on shampoo, so any cheap alternatives would be appreciated!

also, I just purchased and used Pantene Pro V Smooth shampoo and conditioner and don't want to buy a new set until this ones finished, is this okay??

and does my no poo method have to be completely no shampoo, or could I use shampoo say... once every week or 2!