In 1999/2000/2001 it went from R80 to R85 per hour. Only paid for flying time. Nothing for briefings nor late cancellations. Not ungrateful as I can't imagine how I'd have built up those initial hours and networked with the charter companies. Although you wouldn't think so then!!!
Company sorted out renewals for full time instructors, medicals were yours. Managed to pass ATPL in that time too and get a real job.
With the aid of a coloured diagram explain to your student.....