Custom software development costs depend on product complexity, compliance requirements, integration scope, and team structure. A functioning web or mobile app MVP costs $50,000–$150,000. A comprehensive business platform with AI, third-party connections, legal compliance (PCI DSS, HIPAA, and PSD2), and many interfaces costs $300,000 to $1,000,000 or more. The primary cost drivers are compliance architecture depth, the number of third-party system integrations required, team seniority composition, and post-launch support and maintenance scope.