Cosmetologist are not known for being the sharpest crayon in the Crayola box, are they?
First off, most of the "salon" quality brands have parent companies with drugstore brands, such as L'Oreal owns Redken and Garnier. I find the quality to be very similar, probably because they're manufactured in the same facilities. Estee Lauder owns Clinique, Aveda, and Bobbie Brown.
No one is really impressed any more with "salon" quality brands. At one time, yes, those brands could only be purchased in salons by stylists who were trained in the use of the products for different hair types to recommend to their clients.
I have no reason to think the quality is any different in the product I purchase from CVS, Walgreens, Walmart, Target, or Bed Bath Beyond, as from Ulta, Sephora, or Beauty Brands.
I look at the return policy of the store. If I'm not happy with the product, or I think the product has been watered-down in some way, I will simply return it to the store without any cost to myself for shipping and handling.
For my curl type, I still find DevaCurl products to be the best. First, the No Poo contains a mild surfactant, such as Cocamidopropyl Betaine, which is found in regular shampoo, although it doesn't lather. The NoPoo actually cleanses my hair. Next, it doesn't contain really heavy ingredients, such as shea butter.
I just feel like for white girls with Botticelli hair, the DevaCurl line is the better option for now. If there's something new to replace it, I'll try it.
I don't like getting ripped off by salons, charging $44 for a liter, when I can get on sale for $23. That's a big discount. DevaCurl never goes on sale. Ever. And they don't allow coupons. That's ridiculous.
I'm more than happy to purchase it at a less expensive price and an "unauthorized" retailer, as long as I can return it without extra cost to me to the store where I purchased it, if I'm not happy with the salon quality.