Cost of living really depends on which area you live. I live 10 minutes walking from 5th and pay 3500 pesos, this includes furniture, water, gas, internet and cable tv. Electricity is about 100 pesos per month. Groceries I would say around 1500 pesos per month, this can be less, but I want good coffee and nice bread
Comparing friends I am a big spender.....You can live for the same price in a nicer and bigger place but further away. But keep in mind that wages are not much either. I work in on of the best paying hotels, good position and make around 11000 pesos netto per month.