Consumer Price Index (CPI) is widely used to represent the changes in cost of living when determining government subsidies to low income households. Due to the property of CPI as a representative index, however, there may exist discrepancies between CPI and cost of living among different income groups. This study examines such discrepancies by measuring price indices of each income group. Price indices such as Fisher and Tornqvist index which are closer to the true cost of living index are adopted in order to reduce substitution bias. Expenditure weights for the prices of individual items are constructed at detailed level using the Classification of Individual Consumption according to Purpose (COICOP) to enhance the accuracy of the index. The measured groupwise price indices are then used to compare the differences in democratic and plutocratic price index as well as to analyze the changes in real consumption inequality.