Your usual acrylic paint covers 8-10sqm per litre.
Most of these 2 bedroom places are built similarly: rectangle shaped. Since it's 69 sqm I'm going to assume it's 10m by 7m? Well it doesn't really matter. I'm going to cross that space and divide it into 4 rooms. Standard height is around 2.5m. So without taking cupboards/wall tiles/windows into account you have about 2.5*10*4 + 2.5*7*4 sqm of walls. I would deduct around 20% for wallspace that doesn't need paint so you're looking at 140 squares that you need to cover. I'd say around 15 litres should be enough for a single coat.
Cheapest white paint would be around R250 per 20L. But you really shouldn't use that - in just a few short years you will pay waaaaaay more to fix the place up again. Cheap paint adheres poorly and will leave you with peeling walls. Better paint is around R750 per 20L.
I think a lone painter can do the job in 2 days easy. Maybe even a day but you want to give him time to prepare the walls. Labour cost is difficult to guage because it depends on who you find. A "contractor" might charge around R1000 per day, while a painter that sits outside Builders Warehouse waiting for someone to give him work would do it for R200 or R300 per day. These guys also bring their own rollers. Masking tape and crackfiller might add up to R100-R200.
I'm not a contractor, but did some DIY on a new place recently so I'm going off that
