I like, although most people refer to the activity as "trading" not "sales". There are companies that specialize in selling single shares of stock or the like. Some are actual share certificates that are framable as gifts.
Of course it may be taken as the generic "selling of stock" any kind of stock like merchandise (I think in Europe this is used more to denote "outlet shopping").
The .us does work but brings the value down a bit.
$20? (org & biz still open)