There is no inability to understand cents per g's value in comparative estimations. I do it for all products where the volume is comparable. We even have it on many shelf talkers to save customers shenanigan packaging maths as ¢/g or ¢/ml alongside unit price.
I merely contend that toilet paper is not one of them, fully understanding your logic, which is probably why this denizen of dankest Africa hordes it in crisis.