Whole-villa repaint versus just touching up, how do we decide, and what actually drives the cost in Dubai?

Good way to frame it. Touch-ups only genuinely work if the current paint is still sound and you can match the exact colour and sheen, and even then a matched patch often flashes slightly different. Once you've got widespread fading, patchiness, or any damp or water staining, touch-ups just read as patches and a full repaint gives a better, longer-lasting result. On cost, the thing people get wrong is assuming it's the paint, it isn't, it's mostly prep and labour: filling, sanding, treating any damp or cracks, priming, the number of coats, and access like high ceilings and stairwells. Cheap quotes are usually cheap because they skip prep, which is exactly why they fail within a year. So ask for a quote that itemises the preparation and the number of coats, not just 'X per room'. Getting painting services in Dubai to survey and quote the prep properly is what stops the mid-job surprises. The paint is the cheap part, the prep is what you're really buying.