George M. Middius wrote:

The basic fact is that among real speaker makers (i.e., not some
putz assembling products in a storage room he rents by the month),
there is a certain ratio of retail price to manufacturing cost. The
argument is that since Gregipus did not do any actual R&D, and since
a "real" company could build similar-performing speakers for much
less by virtue of economies of scale, Gregipus is attempting to con
and cheat his buyers. There are some big holes in this logic, but
this "debate" isn't really about logic.

You forgot three other things:

1: No other employees.
2: No inventory or warehouse.
3: No storefront/offices/etc.