How do you estimate AI app development costs accurately?

I’ve been researching how teams estimate AI app development costs beyond just engineering hours — including data acquisition, training, infra, and iteration costs.

This article lays out a structured breakdown with real-world estimates and helped me understand budgeting much better: https://www.decipherzone.com/blog-detail/ai-app-development-cost

Curious how others here calculate AI costs for MVPs vs production-scale apps.