Comment by nine_k

Depends on your ROI. If the tool saves you much more, $20/mo could be very reasonable. This IDE is rather narrowly focused on easily doing numerical code and visualizations. If you were doing it every day and were cringing every time at the thought of using your current setup, the product would be for you.

https://xkcd.com/1205/ provides an idea of the cost of the time spent by improving a tool, or, equivalently, saved by paying for it. If you're paid even $50 an hour, a $20 / mo tool that saves you 30 minutes a month, cumulative, is already worth paying for. And this thing can save hours and hours a month for a particular kind of work.