Dropping over a £1000 on a Celta and spending a month doing it when you could be earning more beer money for your trip to china is crazy, particularly when you consider that many FTs won't spend longer than a year or two working in the industry and that the more expensive qualifications don't generally equate to higher wages.

Horses for courses. A celta can lead to a Delta which will increase your earning power in the middle east, and perhaps in China. But someone with those quals wouldn't likely hang around China. As for myself, I only have a BA in English and one of those uni provided tefls you just mentioned.