How much to deduct for damage to bath vanity drawer (MDF)?

[Simon Chang]

Tenant did not maintain bath vanity and it sustained irreparable water damage.

Unfortunately the vender does not sell the drawer face individually, but only sells the entire vanity. Should I guesstimate how much a drawer would cost from the replacement total, or should the tenant be billed for the cost of the entire replacement (minus prorated value for time in use), since I would not be replacing it had it not been damaged.

I'm in California.

[Greg M.]

The current value of the vanity.

It cost $500 and has a life expectancy of 7 years. If it is 5 years old, you charge  (2/7)($500) = $143.