After *05 Oct 2016*: , I figured out a new Trick to change the Primary Domain for Google Apps.
Also i can added 2 more Secondary domains with 5$ per Secondary domain.
I will help you change your primary domain or add secondary domain for your Google Apps (GApps) Free Standard account. Each account are only allowed maximum of 2 secondary domains
Change Primary Domain
Change Your Primary domain. Add Upto 2 Secondary domain more to your account. I can Sell method
Maximum is 2 secondary domain can be add.
Less than 1 day.