I currently develop a powerful JavaScript diagramming library (very different capabilities than charting), and charge more than this, though its done per domain

I currently develop a powerful JavaScript diagramming library (very different capabilities than charting), and charge more than this, though its done per domain and not per developer, with exceptions for OEM customers who need to deploy it everywhere. I'd recommend you go that route instead, most of our customers seem very happy with the model. The charting space by contrast seems significantly bloated to me. This library may well be awesome, but I'd recommend you explain within my first minute or two on the page why this is better than the host of free options out there.