One reason given for external examiners' inadequate remuneration is that academics are already salaried and do not lose this when they do outside work. Ironically, one argument previous governments used for low salary is that academics can supplement it through other activities. Another argument is that the status of being an external examiner is reward enough. I have yet to meet an external examiner who concurs.
Mark Griffiths
Psychology Division
Nottingham Trent University