Out of date you say? Let's see who's out of date.
I bought 2x 20L Plascon Polvin for R1290 each about a month ago from LT Discount Paints here in Cape Town.
Builders is currently running a special for the same paint for R 1,200 per 20L.
I think you're way ahead of time with whatever pricing...
The going rate for a good quality paint (Plascon or Dulux) will cost about R1300 for a 20L drum.
Two coats should cover if the existing walls and ceilings is white.
You will spend approximately R4k if your painter is going to take 2 days to finish the job.