Best 2 in 1 Shampoo and Conditioner

I use plain ol' baking soda for washing , and a little olive oil on the tips of my hair to prevent frizzies. It works great for me and it's darn cheap.

I find the brand I like the best. You can always find coupons and sales to make it cheaper.
I use 2 bottles shampoo to 1 bottle conditioner of same brand, same size. I dump them in a mixing bowl, whisk them and pour back in to bottles. There are times that I need the 2 in 1. I am a swimmer. Some days it is 2-3 shampoos I need as I swim. I never ignore shampooing following swimming.

I also use the conditioner again by itself, but with chlorine water, this makes the best inexpensive way to use the products. I can get my brand in large sized bottles, fairly often on sale.

It's a trial and error process. I personally can't use a 2 in 1, there isn't enough conditioner for me.