Through my years of experiences eating at Hawker Center, one can easily tell by the look of the faces of these hawkers to know whether you will be cheated. One meal is enough to learn a lesson. If you continue to patronise the same shops, then you have chosen to be screwed by these grasslooters. Do not adopt the 70% sinkies mentality, learn to let go of pricey items. The good thing about Singapore is that there are hundreds of Chicken rice stalls to choose from, why pick one that sucks and gave you the bad experiences? Eventually, it is the people power to decide when to allow such "black attitude" to close shop for good. If I am that customer, I would shut up and move on with better life elsewhere.