@analog_cafe @molly0xfff @zoug over at ardour.org, where we charge for ready-to-run versions of our multiplatform DAW, we set the default price to our best guess at the cost of mid-range meal out for two without alcohol, in the country indicated by the request's IP origin. This currently varies from US$7 to US$56.

The (potential) customer is free to change the price to as low as US$1 if they wish.