The costs of Software as a Service (SaaS) app development vary based on factors like complexity, features, platform compatibility, and development team rates. Typically, expenses include initial planning and design, development, testing, deployment, and ongoing maintenance. Small-scale projects may range from $10,000 to $50,000, while larger, more complex solutions can exceed $1 million. Subscription-based models may incur additional costs for server hosting, updates, and customer support. Outsourcing development to offshore teams can reduce expenses, but quality and communication challenges may arise. Overall, SaaS app development costs depend heavily on project scope and requirements, necessitating thorough planning and budgeting.