If you’re the kind of party that prints so much a 5000 page toner bag is worth the effort, you’re not going to be returning single toners to HP. You get a big box and send 50 at once.

Also you should be aware a lot of those toners include some other roll that has a limited life, which means you can’t recycle (or refill) them forever. But if you get toner from a bag you’d have to replace the roll separately anyway. This might be skewing your figures.