It was the "engine-drivers and fitters," we recall, to whom Giorgio directed his Libertarian speeches in the cafe. Note that they honor him by honoring Teresa, another indication of the allegory in which Giorgio's call for Liberty appeals to the people only insofar as it is backed by Teresa's call for material enrichment.
Note also that it is precisely the laborers of the material interests who can afford to pay for the grave. Once again, it is important to point out that Nostromo grants to the material interests the power of creating material prosperity, even among the skilled workers. The objections levelled against it -- and they are stressed in this section -- concern what is lost when material wealth is gained.