Personally I started using like. 75% less TP once I got a bidet. Combined with spending $30 on the bidet itself, that's easy savings.

You can get a cheap one for like $25-50 and install it yourself (pretty easy, not actual plumbing, just screwing and unscrewing a few things) and they're fine. The more expensive ones have heated water, but you don't need that. I eventually sprang for a "nicer" one, but now I feel that was unnecessary. Maybe I'm a freak, but I prefer the cold water anyway.