Costs for RoR development services vary from $50,000 to more than $500,000. You need to consider the following factors: Web app’s functionalities and features: Simple apps have basic functionalities. Thus, they cost less than complex products with advanced features.  Engagement model: The chosen engagement model affects the cost, too. Each option comes with a different level of flexibility, control, and involvement.  Integration: The cost will increase if you want to integrate your app with third-party services, such as APIs or payment.  Technologies: The choice between standard and advanced technologies may reduce or increase the development cost.