Because a Lannister always pays his debts.
By the Pound!
Wa-tah! Haha. I'll leave now... (Sorry if already posted. I searched a little bit but found nothing.)
A refund. credit to (saw it on another post as comment, thought it deserved own post)
GoT because they push twins together to make a king.
Cause they can't stab them in the back
They pay their debts on time.
Because they have so much Antimony!