Build vs. Buy SaaS Calculator

For decades, the build vs. buy decision followed a familiar script: buy commercial software when a vendor solves the problem well enough, build internally when your needs are too unique or strategic to outsource. The calculus was mostly about cost, timeline, and internal capability. AI just tore up that script. Today, a small team with access to foundation models and modern development tools can build sophisticated, custom software in weeks — not months or years. At the same time, AI-native SaaS vendors are embedding capabilities into their products faster than most enterprises can evaluate them. The old framework — the one built on assumptions about build cost, vendor lock-in, and competitive differentiation — wasn't designed for this environment. That's the problem Harry is built to solve. Harry is the AI agent at the heart of the Differential Factor Build vs. Buy Calculator. He doesn't just run you through a checklist. He asks the right questions, listens to your specific situation, and helps you think through the decision with the nuance it deserves. Harry guides you through the key dimensions of any build vs. buy decision: Strategic fit — Is this capability core to your competitive differentiation, or is it infrastructure? The answer matters more than ever when AI can commoditize entire software categories almost overnight. Total cost of ownership — Not just license fees vs. development costs, but the full picture: integration, maintenance, talent, opportunity cost, and the hidden costs of vendor dependency. Time to value — In a fast-moving competitive environment, speed matters. Harry helps you think through realistic timelines for both paths, including the AI-assisted build scenarios most traditional frameworks ignore. Risk and lock-in — Vendor concentration risk, data sovereignty, switching costs, and the growing risk of under-building in areas where proprietary capability may become a decisive advantage. AI leverage — This is where Harry is different. He explicitly factors in how AI tools are reshaping internal build economics, and whether AI-enhanced vendor solutions actually deliver the differentiation they promise. Enterprise software is in the middle of a classic disruption cycle. AI-native tools are entering from below, offering good-enough functionality at dramatically lower price points. Meanwhile, AI-assisted development is collapsing the cost and time required to build custom solutions internally. The result: the traditional "buy unless you have a really good reason to build" default is no longer safe. Neither is reflexive building. The right answer depends on a careful, context-specific analysis — and most organizations are making this decision with outdated mental models. The Build vs. Buy Calculator exists to change that. It's grounded in Christensonian disruption theory and practitioner-informed research into how AI is reshaping enterprise software economics. Every conversation with Harry contributes to a growing body of research on how organizations are actually navigating these decisions in the AI era. The Build vs. Buy Calculator is designed for: * Technology and product leaders evaluating whether to build AI-native capabilities internally or adopt a vendor solution * Founders and operators deciding where to invest scarce engineering resources versus where to buy time-to-market with commercial tools * Strategy and finance teams stress-testing assumptions in software investment proposals * Innovation and transformation teams inside enterprises trying to move faster without accumulating vendor dependency debt If you're staring down a software decision where AI is either part of the solution being evaluated or part of the internal build capability being considered, Harry can help you think it through. The Build vs. Buy Calculator is FREE. No paywall, no sales funnel. Harry asks questions, you share your situation, and together you work toward a clearer decision framework. Differential Factor is