Agile can be cheaper than waterfall for a few reasons:

1. Adaptability: Agile allows for changes to be made throughout the project, which can prevent costly mistakes later on. In waterfall, changes are harder and more expensive to implement once the project is underway.
2. Early feedback: Agile involves customers throughout the process, so any issues can be addressed early on, reducing the risk of expensive fixes later
3. Shorter cycles: Agile breaks the project into smaller, manageable parts, so teams can identify and fix problems sooner, saving time and money
4. Focus on value: Agile prioritizes delivering the most valuable features first, so resources are spent on what matters most to customers, potentially saving costs on less important features.

While Agile can be cheaper in many cases, it depends on factors like project size, complexity, and team expertise.