Here is the secret about registering a domain name for less then its regular price. Whenever you decide to register a domain name at GoDaddy.com, register it using the following strategy. Search on Google entering such keyword phrases as “discount coupons godaddy”, “discount goddaddy”, “coupon code godaddy” etc. This way you will be able to find a discount code for your domain. Some of coupon codes might be expired, but after several searches you will find a valid coupon code.
When you get know this code, at checkout you enter your code and Godaddy will give you at least $1 dicount from regular price.
Coupon codes works on domain extending as well.