When buying tea in Taiwan, we had to use the traditional unit of measurement, the jin (斤) translated catty, which corresponds to 600g, instead of metric measurements which are widely used in Taiwan as well.
We may have used traditional units of measurement because we were in a rural area, dealing with an industry that was established before the introduction of the metric system, and has continued to be run on its own terms as most tea in Taiwan is sold domestically.
Apparently in town vegetable markets, traditional measurements are also used as well, which again suggests that where an industry is not international, the metric system is not used.
Incidentally, the quantity of 1斤 is different in different places, at around 605g in Hong Kong and 500g in Mainland China. In Taiwan and Hong Kong, it is 16两 (liang) to a 斤, but in Mainland China it is 10两 to a 斤. If you happen to buy directly from these three areas, please bear in mind that the weights are different.
Image: By Naval History & Heritage Command from Washington, DC, USA (2013.114.022 Scale, Pharmacy) [CC BY 2.0 (http://creativecommons.org/licenses/by/2.0)%5D, via Wikimedia Commons