I feel PUREX is the most cost effective detergent on the market today. I am speaking from experience.
When I was single and living on my own, I always purchased Tide. It did work well for me however,it was very expensive.
Things changed when I got married and had 2 children. I went from doing two loads a week to at least one load of laundry every day.
My husband is in the construction business, so I need to use a detergent that cleans well. The price of Tide started to become too costly for me. I decided to start trying less expensive brands of detergent.
I tried quite a few and ended up sticking with PUREX. It really works just as well as tide. I like the smell and the results it provides.
I do pretreat stains with shout, but even with tide I had to do that. I think if you wash your clothes properly (for example; don't over stuff the washing machine) you will be one hundred percent satisfied with Purex.
With a family of four and a weak economy, I need to cut corners when I can. This is definitely one of the most efficient ways to do your laundry.