A coleague of mine was eating it when he was on a diet to lose weight. It's basically kebab/gyros meat and a vegetable salad with a dresing (usually tzaziki). You have basically no sugar in it, it's just protein and vitamins.
Back in the day it cost like 4-5 € where I live which was pretty cheap for a lunch. Now it'd more like 6-7 € but that's still decent