That’s the replacement cost: what it would cost to buy a new harp that’s roughly equivalent to what you have. Unfortunately, it’s not a resale appraisal–that is almost always much lower.
Forgot to explain that the replacement cost is important for insurance. It helps determine what you can expect to get if something happens to it. Some insurance just pays the replacement cost if a harp is lost, but these days many policies use that as the base to figure out just what it’s really worth and deduct for the age of the instrument. I think Anderson does this, for one.