The tea in China

"for all the tea in China"... this is a negative sarcastic remark, correct?

Yes. From a previous discussion:

Since China is a large country, it would contain a lot of tea -- and the tea would be worth a tremendous amount if it were made available on the world market. "All the tea in China" therefore translates to a considerable fortune. If you said "I wouldn't do that for all the tea in China," it means: I wouldn't do that even if you paid me an enormous fortune.

Negative, yes. Sarcastic, no. SS