Public sector doctors cannot charge extra because they are governed by the ministry of health. On the other hand, private medical specialist can charge as long as the patient is willing to pay.
Accordine to a prominent medical personality in Singapore, an Indonesian was charged $100,000 for a simple laparoscopic removal of a gall bladder, a procedure that probably would cost $10,000 if he has the time to shop around.
It was also stated the charges also depends on how the patients are dressed, where he comes from and the amount of jewellery he wears.
The patient is also at the mercy of the doctor because he may be requested to go for procedures that may be unnecessary, such as blood test and radiological examinations where the patient would be in no position to refuse.
So in order to save cost and to pick the most reliable medical specialist, it is still best to shop around town.