Again, this depends greatly on the location in which you are teaching. In Asia, or elsewhere if you work full-time for a public school, you are likely to sign a contract with a guaranteed salary. You should be able to live comfortably on this salary, and maybe even save some money, especially if the organization subsidizes housing. However, in many situations it is difficult to support yourself working for just one school. Teachers usually compensate for this by teaching private classes on the side, working for several schools (if permitted by local visa/contract laws), or having some money saved up before they venture abroad.