Who in their right mind would say that paying an extra 100,000 as a developer tip is fair. Do you tip when paying for a car, an airline ticket, insurance, etc. Do you honestly think it would cost +QR100,000 - 150,000 to put air-conditioning in a villa? Go to Carrefore, price the most expensive split air-con unit and then times that by 6 aircons for a 2br unit. You are not even near the QR100,000 you say is justified.