I just found this while looking through some old books. I'm not sure what "artists are capable of earning $30, $50, $75 weekly" means - maybe if you're commissioned on a Friday you're meant to get more money? I wish I'd been aware of this archaic loophole earlier.
"Copy this sketch for free criticism"; sound familiar?
*EDIT: I just re-read this post and realised how negative I sound today; it's unintentional. Maybe if I'm aware of it does that make it better? Yeaaah...