Are there any opensource billing and invoicing extensions available for LENS?

Looking to build a datacenter billing software and looking for guidance, so that we don’t need to start from scratch.

We checked so far
Open Cost - It is only observability platform. This can be used a starting point for metrics collection.

Then we need a rate plan, various ways to modify or give discounts on the rate plan based on usage, volume, time etc.
We looked at Kill-Bill as a viable solution, but seems a bit overboard.

If someone can give pointers, we are happy to share our product to the community as we develop.

Not sure this is what you are looking for GitHub - kubecost/kubecost-lens-extension: A Kubecost extension for the Lens K8s IDE that adds namespace cost data.