Slughorn declara (em HBP) que os professores de Hogwarts realmente recebem um salário. Evidentemente, é muito insignificante, de acordo com o argumento geral de que professores britânicos são mal pagos:
Slughorn seemed to be talking more to himself than Harry now.
‘… seems an awful waste not to collect it … might get a hundred Galleons a pint … to be frank, my salary is not large …’
And now Harry saw clearly what was to be done.