Not all contractors and renovation companies are equal. A good estimate should be a detailed list of everything that will be included in your project. Although costs may vary based on materials, you should get an idea of what you can expect to pay for each service listed in your estimate. Some estimates may include line items for unexpected expenses that don't end up occurring; other may come with detailed explanations about why certain elements cost more than others or fall outside of an expected range. Whatever is included, your contractor or company should be able to clearly explain how they came up with their estimated price (including sales tax and labor) when providing you with an estimate of cost for bathroom renovation.