Costs, and time.
If going back to China, what stuff you need to prepare ?! Just returning home, that is simple, if you think it this way.
I would think going to other places involving more trouble - travel arrangements, accommodations, etc etc
If you wont go back to China, then pick the method involving the least time as it seems the costs do not vary a whole lot.
So you are going to Cambridge ! I were you I would definitely go !