I wish more models would advertise them like they do here... So often I see "for rates, please PM" or "TFP if your work matches my port"
Of course that leaves the door open to models asking for either Pay or 'more' pay if the photographer's work either isn't good enough or is a style not compatible with her existing port, but it also means I wouldn't be in the position of saying "no, that's too much".
Which is invariably interpreted as 'I don't think you're worth that much' and often results in getting blocked... :/