Great product for wavy/curly hair. I've used many oils/serums including all of the argan formulations and this one takes the cake. Smells wonderful as well without a heavy fragrance.
However, as far as where you purchase it...Sleekhair.com has the same size/same product and is A LOT less expensive. On BB it's $38.00, and on the other website it's $29.99. You do the math, but wherever you buy it you'll like it.
I still love you BirchBox!