Grandfathered Price Drift Monitor

A founder promised early customers they could keep the $19 plan forever. Six months later, a checkout cleanup moves some of them onto a new $39 price ID, while others remain on the old plan but lose one included feature. Nobody notices until a customer sees the renewal email and asks why the promise changed. Grandfathering is trust-sensitive, but the mapping usually lives in a mix of Stripe prices, database flags, and old launch notes.

Let the founder define each grandfathered cohort, expected price IDs, included features, and renewal rules. The monitor compares live billing and app entitlement state against those rules and flags customers whose legacy promise no longer matches reality.

Indie SaaS founders and small teams of 1-10 who have legacy customers, annual plans, price migrations, or public grandfathering promises.

This is a beginner-friendly micro-SaaS idea, ideal for first-time builders or developers looking for a manageable side project. Ideas at this difficulty level typically involve straightforward architectures, well-documented APIs, and clear user flows.