Assuming that the output always looks like:

You purchased 22,000 Turrets for $3,941,080 (including tax).

You'd use:
Code:
on *:text:You purchased*including tax*:#: {
  var %price = $calc($remove($gettok($1-,$calc($gettok($1-,0,32) - 2),32),$chr(44),$) / $remove($3,$chr(44)))
  msg $chan Unit Price: $calc(%price * .06) Demo: %price Comm: $calc(%price * .09)
}


The var line is a bit complicated because I made it to work regardless of whether or not the item name is 1 word or not. If it's always 1 word, you can use this var line instead:
Code:
  var %price = $calc($remove($6,$chr(44),$) / $remove($3,$chr(44)))


As you can see, it's much simpler, but it won't work if your item name is more than 1 word, such as Machine Guns.