A list of companies that provide domain name registration can be found at InterNIC's Accredited Registrar Directory.
The prices for domain names vary widely. Some registrars offer significant discounts for purchasing a domain name for a number of years, or include it in other services such as hosting. So you can get a domain name for free if you are purchasing other services. Typically, you should never pay more than $8 to $10 per year for a domain name purchased without other bundled services or Web hosting.
More information on domain names is available from InterNIC.
