I’m not sure where I have ever read that Google entered into an exclusive arrangement with any domain registrar but it looks like they have done so
Either registrar will set you back just $10 for a domain registration but that are the only two choices you have.
“”Google doesn’t register or host domain names. We’ve partnered with a few domain registration partners (registrars) that offer these services because it’s a lot easier to set up a Google Apps account this way. Continue with the pre-selected company or choose another one of our trusted domain registration partners to fulfill your request. Your new domain will be pre-configured to work with Google Apps so that you won’t need to manually modify your DNS settings.”
However the only two choices you get are to use Godaddy or Enom.
For your $10 you get:
|“””One year domain registration for $10|
|•||Private domain registration to protect against spam at no extra cost|
|•||Full DNS control and domain management|
|•||Automatically configured to work with Google services|
|•||Email, calendar, instant messaging, web pages and more also at no extra charge”””|