CPT could / should really not ask for more money. JNB central and east neither. I reckon they should be on even par with each other, as all three of them do equally little. JNB itself though is a different kettle of fish.
Maybe Central and East's allowance is justified by them living, commuting, working, ducking for cover etc etc in Gangsta's Paradise.
PS. For those interested, European ATCs earn around R10'000 (subject to currency fluctuation) per month in station allowance, working close to 2000 flights a day in a piece of airspace the size of the Lowveld!