A bidet. You can get a basic one for $30-$40 and there is no need to get anything fancier than that. With the amount of money you save on toilet paper, it will more than pay for itself in the first year.

Additionally, toilet paper will never clean your rusty balloon knot nearly as well as a stream of water. If you got shit on your hand, would you be satisfied with wiping it off with some paper? I hate pooping anywhere else but shit-base-alpha. Whenever I have to poop somewhere and use toilet paper, I feel like a filthy caveman.