What state are you in? Different states have different laws. But you're correct about the depreciated value of the carpet. They cannot make you pay 100% of the replacement cost. You would only be responsible for a pro-rated amount, based on the age of the carpet and the useful life. Let's say that it was five years old. The carpet started to accumulate wear and tear starting the day it was installed. By the time you moved out, the carpet lost a lot of value based on the accumulated wear and tear. The landlord cannot charge for that loss of value - they can only charge for the remaining value. Different people have different timelines, but 7 years is pretty standard for a carpet in a rental unit. Anything more than that, and the landlord is pushing it. Most landlords use cheaper carpet in rental units, and it should not be expected to lost 10-15 years.
Did they give you an invoice that shows it was $2500 to replace, or was the $2500 already a pro-rated amount? If that was the full amount of the invoice, I would write back and say that you dispute the charge because the upstairs carpet was already past its useful life so there should be no charge, and the downstairs carpet should be pro-rated based on its age (if you lived there for a year, then it was a year old by the time you moved out).
