Kebab World, located in the food court of the Australia on Collins centre, is my go-to place if I want a kebab for lunch on a weekday. Their kebabs are pretty tasty, and cost $9.20 (you can get deals with a drink and chips for a little bit more). For something different, try their toasted gourmet rolls - at $9.50 its marginally more expensive but worth it. I especially love the satay chicken roll!
Service is friendly and because its in the food court there's plenty of seating available. This wont be the best kebab you've ever had, but its still pretty darn good and conveniently located right in the heart of the city as well!

Approximate cost: $9.50