if it is well taken care of- stored properly- used gently- and saved for your grandkids/great grandkids they may have a real treasure- location matters, timing matters, the current market matters- just like with stocks- values go up & down- but any quilt- amish or not- if it is appealing, has excellent craftmanship, visual appeal, and a (timeless) design if cared for will at some point increase in value....if taken to the right place at the right time.
appraisals go up & down constantly- one quilt i have has been appraised 3 times- all 3 times the value has been very different than the time before- and started high-went way down- then bounced back up even higher====it all depends and doesn't really matter if it's Amish or any other style.