Comment by charcircuit

>I'd urge reading up on revealed preference and product discovery

I'm not sure what point you are contesting.

>It's worth picking this apart.

They were rhetorical questions.

>price-inelastic demand

With this you could argue that the absolute price does not matter, but the relative price between products that can substitute each other do. In this comment chain it is being argued that this kind of device wins on relative price.

>Sales are a mechanism for drumming up demand for a product, with the hope that the additional volume will compensate for the marginally lower margin.

It is for increasing demand, but making a higher rate of profit on the item is not the main reason. Things like being able to clear inventory, or to learn about what the current demand curve looks like (to know if prices should be adjusted) are more common purposes.