comparing the cost of a big mac may show the purchasing power parity amongst difference countries.
Use your own country and I'll convert it here to USD or something.
EDIT: big mac prices listed below
Germany - 3.99 EUR or 4.83 USD
Singapore - 5.75 SGD or 4.34 USD
France - 4.80 EUR or 5.83 USD
USA - 5.00 USD
Oman - 3 OMR or 7.80 USD