It is not easy, but that is something that the client needs to research.

Unfortunately, for these types of things there isn't an easy way to figure it out.  You can't really search eBay or Craigslist to figure it out.

One POSSIBLE method would be to estimate the real life expectancy and base things on that.  So although carpet is depreciated over 5 years, if the client antipates it will be worn out and replaced when it is 10 years old, it could be logical to estimate the FMV of the 2-year-old carpet is 80% of the original price (8 more years out of expecting it to be used for 10 years).