Fair compensation for 12 year old curtains damaged by tenants

Hi All,

My first post here :)

We rented a house in Harrow, London, for 2 years. Shortly after moving in, we replaced the landlord's living room bay window curtains with our own, storing theirs in the shed. Unfortunately, we forgot about them when moving out. The landlord later found the curtains ruined, likely by mice, and is demanding £250 in compensation.

I acknowledge it was our mistake for not taking proper care of the curtains. I’ve offered to replace them with similar ones from Ikea or Dunelm (which I think should not cost more than £75–£100) or provide reasonable compensation, but the landlord insists on £250. They’ve now provided a 2012 receipt showing the curtains cost £190 plus £75 for fitting, claiming they were custom-made.

Given the curtains are 12 years old, I feel £250 is excessive. If we take this to TDS for dispute, would they consider depreciation from the original cost? Or would they focus on cost of a replacing with a new one now, which can vary greatly based on taste, quality etc? I am looking for advice on a reasonable amount and what might happen if we were to take this to TDS dispute?

Thanks