Price is a regional thing. where i live this would be cheap because there aren't many LA in the area so you don't have as much choice which keeps the price down.
what i will comment on is the workmanship. if she did not do exactly what you had discussed with her and didn't call you to explain why she feels the discussed design won't work then you have every right to have your quilt skinned.
i would insist that she skin the entire quilt and you two must come up with an agreed upon plan or skin the quilt and give me my money back.
to me this is the only reason to work with local LAs, you can run over and discuss problems/challenges and be a part of the solution.
she went against everything an LA is supposed to do and she should have known better then to just alter the design plan without your input.