http://simplemom.net/how-to-clean-yo...thout-shampoo/
This may seem outrageous but if the cost is really bothering you, you may want to consider it. I know a number of people who have really liked the affects and I just started trying it yesterday. My hair still feels clean and maybe even a little softer. It may get oily or frizzy for a while while the oils rebalance (shampoo causes you to overproduce them) but it's an alternative