Toilet paper
You may think you are paying less for more, but you aren’t. The large pack for an affordable price looks tempting, but the issue is that these rolls are much lighter than brand-name products. Just take one, and you will see that they are fluffy, not compact. That means there are fewer sheets in the role.
Also, these cheap toilet paper rolls are often one-ply, so you need to use more of them, and you will run out much quicker. Paying more for a brand-name product is probably cheaper in the long run.