An expression which means "a lot". Also, expensive, or a lot of money. When negated, it means "not at all". I love this one example I found on a German website devoted to English idioms:

Would you like to live in space?
Not for all the tea in China!

There is also an example from an episode of The Family Guy:

(Peter sees "Free Tibet" protestors outside the White House.)
Free Tibet? I'll take it!
(Later, on the telephone)
China? I have something you might want, but it's going to cost you. That's right, all the tea.

Naturally, this expression comes from the fact that in China, they drink lots of tea. According to the U.S. Department of Agriculture, in 1985 All the Tea in China would have been somewhere around 600,000 tons.

There is no definitive answer as to this expression's origin. Some say American, some Australian, some British (since the British drank most of the exported Chinese tea). It's lost in the mists.