Realtime functionality is now a crucial expectation for users across various applications such as online communities and remote collaboration platforms. Organizations often face the dilemma of whether to buy or build their own realtime infrastructure. This article discusses the costs associated with building in-house realtime infrastructure, including initial construction, ongoing maintenance, and opportunity cost. It emphasizes that building realtime infrastructure is resource-intensive and can divert time and effort away from core product functionality. The article also highlights the benefits of using a Platform as a Service (PaaS) provider like Ably to reduce costs and focus on delivering unique product features.