When you have a tradeskill for which you need to buy large stacks of trading items it is very uncomfortable.
Either you rightclick and get only one item, or you shift-leftclick, have to enter a number and then have to manually put the stack in your bag.

Here comes BuyStack!
When you CRTL-rightclick on any item at a trader you automatically buy a whole bunch of that item that is put directly in your bags.

These are the options:

/bs option [value]
size 'value' -- set the stacksize to 'value' (default 20, min. 1)
s[ettings] -- list the current settings.

The key is hardcoded to CRTL-rightclick at the moment, but if at a later time any other addon or the default ui might get in conflict with that, I will make it configurable.

ATTENTION: THIS ADDON USES LIBSLASH. PLEASE MAKE SURE YOU HAVE IT INSTALLED.