Don't do anything you don't want to do

Personally, if I were in your situation, I would go for it. I wouldn't worry so much about the money because as we all know, it appears out of nowhere when it's absolutely necessary. I would love the adventure. But that's me.
Liz's questions are right on the ball. Is there a reason they picked you for China, maybe they see some potential for you over there? Or is it like you indicated, purely luck of the draw?
You have every opportunity to visit China later on in your life. You should go with your instincts and if they tell you that this is not the right time, then don't. Don't feel pressured to do something you aren't comfortable doing. One the one hand, you won't see China right away, on the other, you will get to visit someplace else that you might not otherwise be able to so easily. Plus, it might cost less.