I think I paid $40 for 1 quilt appraisal, if I remember correctly. It was during a quilt show and it was a 30 minute written appraisal. I had to make an appt - I couldn't just bring it to the show w/o an appt. I was pleased that my g-grandmother's quilt was valued at $650! She asked me a lot of questions, laid the quilt out on a table and really looked it over.
I think there are also verbal appraisals. My local guild is having a show this weekend and there will be an appraiser there. I wish I had planned better cause I have a couple more quilts I would like appraised.