Thanks for sharing examples. These along with music related examples appear to be of one quick transaction of a fixed specification product with no commitment of ongoing support unlike 'longer duration' courses from Coursera or a subscription based ongoing relationship. Also these examples seem to avoid the free option and offer a broad pricing range.

A quick 'back of the envelope' estimate of revenue and cost of BandCamp service (enough public info available) seem to suggest this pricing model might have low profitability.