Baron said:
In my case it was also time to change the idler pulley and belt tensioner pulley (at 100k), pretty easy, around R800 in parts.
By way of bitter experience.......:
All of the above and would second the idler + belt tensioner pulley.
Might as well change the water pump and thermostat at the same time, as the water pump will definately seize at some stage. Use OEM only!
Also: if you are buying anything, make sure to see if it has not already had head work, in which case, it has already overheated once before.
Walk away if you have any doubt, especially if she has no records of maintenance.
E46's are even less tolerant of neglect than most German cars!