Building an app like QuickBooks typically involves significant costs due to the complexity and features required. On average, the development cost can range from $50,000 to $300,000, depending on factors such as the platform (iOS, Android, or web), design complexity, security requirements, and additional functionalities like tax calculation, invoicing, and integration with third-party services. Customizations, data storage solutions, and scalability features also impact the total price. Hiring experienced developers or a professional app development company like Dev Technosys can ensure quality development but will influence the overall cost depending on the project scope and timeline.