The dilemma of whether to build or buy a billing system is challenging due to the complexity and critical nature of billing, which serves as the financial backbone of a company. While building in-house can offer cost savings on subscriptions and customization, it often results in high maintenance demands and potentially overwhelming complexities, especially with variations in regulations, billing cycles, and customer needs. Conversely, purchasing a ready-made solution like Lago provides advantages such as accelerated implementation, scalability, and robust technical infrastructure, which are crucial for handling usage-based billing requirements efficiently. Lago, an open-source billing platform, facilitates rapid deployment and supports a variety of pricing models, offering flexibility through cloud or self-hosted options. Despite dependencies on third-party systems potentially limiting flexibility and creating bottlenecks, the comprehensive features and integration capabilities of commercial billing solutions can significantly enhance revenue recognition and customer satisfaction. Ultimately, the decision to build or buy should consider core business competencies, resource constraints, and market timing, with platforms like Lago presenting a strategic choice for companies prioritizing speed, scalability, and innovative pricing models.