The product I am talking about is my SaaS starter kit supastarter (https://supastarter.dev). 

It essentially is a codebase that comes with all the common SaaS functionalities like auth, i18n, payments and so on already implemented.

I started to over a year ago in August of 2022 to build the initial Next.js starter kit for myself, so that I would not have to repeat myself over and over again when starting new SaaS apps for my clients. I never really had the intention to (in the beginning) to make real money from this, but I created a small landing page and put a price tag of $49 on i, which would get you access to the repository and a Discord server for support. I said to myself "If this thing makes me $1k, it's a huge success for me", not believing that could actually happen.