If you have more than 50 domains registered at NameCheap, you can contact customer support and ask for the special GOLDDEAL coupon code to be enabled on your account.
If you have over 300 domains registered with them, you can ask for the DIAMONDS coupon code to be enabled on your account.
DIAMONDS lowers my cost for a com/net/org registration to $8.41. It does the same for domain renewals. :)