I buy the liter (33.8 oz) bottles at Sally's or at sallybeauty.com.
The liters usually cost from $20.00 - $25.00 (depending on sales, club discount, etc.) Last time I checked, the 32 oz bottles of Wen cost around $50.00, which is why I've hesitated to even try Wen. I'm so happy with Hair One, I'd hate to like something more that costs twice as much! I am very glad the first Hair One I used was the Argan Oil, because if I'd tried the Olive Oil first, I may not have wanted to try the other formulas.
I didn't try Hair One for the longest time because I was afraid of the amodimethicone. I still avoid SLS and ALS completely, and I doubt I'll ever let either of them near my hair again. I truly had been stuck in the "cycle" of parching my hair with shampoo, then coating the scorched remains with silicone products. My hair didn't even feel like human hair anymore. After my 1 year anniversary of being 0 sulfate, 0 'cones, I started getting curious.
I'm a science person, so, by nature I live
to experiment, and now I'm in a continual process of analyzing my hair's response to any ingredient I can isolate. I'm not "afraid" of silicones anymore (I used to treat them as though touching a bottle containing them would make my hair ignite into flames), now that I know to watch out for build-up and or dryness. But they are definitely not something I would use in my regular hair routine. Except for the amodimethicone in the Hair One, I still avoid other silicones 95% of the time. Occasionally, though, an outstanding product comes along that's worth a cleansing with something containing cocomidopropyl betaine. (There are a couple of curl creams that are worth the occasional "cheat".)
I have been using the Hair One Co-wash with success for 2.5 months. I use it as a wash, and as a leave-in. For me, if the amodimethicone is
creating a build-up, it's either not yet apparent, or it's a positive build-up for my hair. I have done one clarifying cleanse (I used A.S.P Kitoko) since I starting using Hair One, but it was to eliminate styling products I'd been experimenting with. My hair is naturally extremely dry, and the ends are continually fried and frizzy. However, my hair is noticeably growing. Perhaps the amodimethicone helps with breakage?
In any case, so far I do not believe my hair has a problem with amodimethicone, and it may actually be a good thing for my hair...