The problem with replacing carpeted stairs with something else(except thin tile) is the code (and safety) rules for the rise of the steps. The difference in the rise(height) between all the steps in a stair cannot be more than 3/8". Where that is the problem is the rise of the first(bottom) and last(top) step. That rise is designed and built into the stringers.

That means a stair designed to be carpeted cannot have any material thicker than 3/8" added because the top/bottom steps risers will be in excess of the code.

If you are selling, least expansive fix is to replace the carpet with an inexpensive type of carpet. That does two things. Makes the areas look nicer and allows the new owners to do what they want with less cost.

Kim you're right! Thanks!