Suave shampoo or conditioner costs $1 for 22 oz.
Since I got it in my head that it's worth it to spend $35 for a haircut now (it totally is, my haircutter lady Kate is fantastic, well except she keeps trying to get me to cut my hair not like David Tennant, but I got called Matt Smith the other day (no lie) so it's fine she's great, and also she got me back into 80's music), anyway since I got it in my head that it's worth it to spend $35 on a haircut, I figured well I might as well buy some good shampoo and conditioner to maintain my hair nicely and not hurt it real bad with awful chemicals or whatever. So when she asked if I needed any product (I think that's the word she used, because y'know "hair products" do not have an S on the end) I resisted the urge to snap "I would if I looked like David" and instead suavely (har!) asked her for a shampoo and conditioner, whatever she recommended for my beautiful new Matt Smith locks. Turns out it's "Mop" "Glisten" organic shampoo and conditioner.
Seventeen Dollars Each for Eight Point Five ounces.
Hey, that divides nicely: two dollars an ounce. Which means it's (roughly) (not actually roughly, actually pretty exactly) forty four times more expensive than cheapman's shampoo. The only other item I can think of with a 44x variation in cost that I'm likely to run across in daily life is salt.