Most large asian and european carriers now charge for checked bags over 20kg. You get 20kg free, then, for international flights, they charge 10-15 USD (or Euros) per kg. 100 lbs might cost 400-500 USD.
Some asian carriers are even charging for carry-ons over 7kg. If your bag weighs more than 7kg, you pay the same rate for kg over 7. It is getting painful.