The time it takes to get an estimate depends on the complexity of the project. For a simple project, you may be able to get an estimate in a few days. For a more complex project, it may take a week or more.

You will need to provide the estimator with as much information as possible about your project. This includes the scope of work, the materials you want to use, and the desired completion date.

The accuracy of an estimate depends on the information that is provided to the estimator. If you provide accurate and detailed information, the estimate will be more accurate. However, there is always some uncertainty in an estimate, as there are factors that cannot be predicted, such as changes in the market price of materials.

If the estimate is wrong, you may need to renegotiate the price of the project. In some cases, you may be able to get a refund for the difference between the estimate and the actual cost of the project.