THIS IS A MAJOR SCAM! First of all, you don't need to pay a company to appeal your property taxes. You can EASILY do it yourself. Simply file a case with your local property tax assessor's office. They hire an appraiser to give a valuation to your property and simply reduce your taxes according tothe new assessed value.
Second, Hillary Koster is a scam artist appraiser with multiple complaints at her state board. She is being investigated for fraudulent appraisals in multiple cases and likely can no longer make a living so she has truned to conning people out of money to fill out paperwork which they can easily submit on their own. She makes it sound like you need an expert when you don't!
She takes your money up front so you're stuck. Additionally she then charges you through the nose for her appraisal services. If you don't like her price for the appraisal, you forfeit the money you paid up front for disputing your property taxes (which you can easily do yourself). RUN! Don't walk away from Hillary Koster and Tax Appeal Express. Save your money and do this yourself. It truly is very, very easy!