Words Which Mean Their Own Opposites, Part 2

Another word that means its own opposite from AC Muller's CJKV-English Dictionary:

沽

To sell (an article, object).

To buy.

A wine seller.

A huckster, hawker, peddler.

Negligent, careless, remiss.

Though, I think if a word means "buy" and "sell," it might be better understood as meaning "trade" or "barter."