There are so many variables when it comes to toilet paper. Not only do you have the size of the roll, but the ply and the quality of the paper and the way that they attach the layers together. It’s akin to thread count in sheets. Some of them you can use less of to do the job, but a lot of people tend to grab the same amount, no matter what.
If you go by number of sheets per roll alone and compare that for the same type of toilet paper, the price then depends on the retail sale gods that week. I’ve found a package of smaller rolls cheaper than the double or even the biggie super ones. You just have to do your unit pricing if that is the way you decide to go. Then you have the tough stuff vs the soft stuff debate, one can use less of the stronger stuff for the same job, but then it becomes a personal preference issue. Same goes for Kleenex. The seemingly more expensive Boutiquey stuff, can be less expensive in the long run if you are only grabbing one sheet instead of two or three…and now I must go, I can’t believe I just wrote that. I guess we could all just go back to corn cobs and end the debate that way.