I've had a number of quilts appraised- have always felt it well worth the cost- especially if you are giving an expensive (heirloom) quilt to a wedding couple or some other occassion- it is nice to include an appraisal so they can include the quilt in their insurance inventories---if you do not have documented proof of the value of a quilt and you have a disaster (like a house fire or flood) the insurance company will only allow the cost of a blanket you can go to the store & buy---not the *claimed value* unless you have the appraisal---
AQS has certified appraisers across the country- if you visit their site you can find the list sorted by state- find one in your state & give them a call---it is a great experience -- you do not have to have an old/antique quilt to have one appraised- i have a friend who made a 'one block wonder' quilt - and it appraised for $1800! she was THRiLLED!
I've had quite a few of the quilts i made appraised- some before sales, some before gifting.