Calculate the average price and make some adjustments

calculate the average price of a mobile phone tariff based on given rebates. the site is a comparison site for mobile phone tariffs. on the sites all tariffs are listed, however i have a problem with some tariffs, the problem i will tell you also i will tell you the name of the website if you ask me. so make sure, you ask me questions, so i get the feeling, you care about the project and we can discuss things. i will give 120$. if you have time you can make it within 3 or 4 hours. so that makes 30-40$ per hour. i need a fast coder, who wants to finish this project today or tomorrow.