Concerned about a Teaching position in China and China visa application.

I am also offered a teaching position in china and asked for pertinent docs and have already complied all. I am to pay first my my back and forth airfare and pay for the working visa. I have not seen the contract but I know they will reimburse me after some time period. I am free of board and lodging with allowances. I dont know if this is safe process? I thought the visa was part of what they paid for but I dont know. I also complied info and sent thru emails all the docs that they required of me to produce. please send me advice of how safe is the direct hire and am i not risking myself paying the airfare and paying for visa here?I am at the begininning of this process so I want to make sure that it is okay before I proceed just as the last person.. I just want to know how safe i am in continuing this application. all my thanks for your support. :)