Fees will vary from state to state and city to city. However, hiring an experienced immigration attorney, especially in assembling a Hardship Waiver application will be well worth the money that you pay. You do not want to waste time or opportunity by trying to do this yourself.
Even within just this limited area, prices can vary, depending on the client and the facts of the case. You will bet be served by finding an attorney with whom you fell comfortable. Choose what you can best afford.