Google is ending their Google Checkout service, it closes 11/20/2013. The support document on this discusses retiring Google Checkout Merchant.
That's now how I used Google Checkout though, I used it as a way to manage net purchases . This is where things get confusing; because while merchant use of Google Checkout is dead, my transaction history survives with Google Wallet. As best I can tell Google Checkout non-Merchant became Google Wallet . It lists, for example, all of my Google App related transactions, Google Storage  and domain registrations.
Ok, the last may need some explanation. Years ago, before Google wed Verizon under the red moon and drank the blood of innocent children to become the Dark Lord of the Net, Google Apps was launched as a freemium service. Anyone could sign up for a domain (most often managed by eNom) and get the full suite of Google Services for up to 20 people (or maybe more). All the payments were managed through Google Checkout, so there was one place to manage charges.
Those were the glory days. I know it's hard to remember a time when Google wasn't a synonym for Evil, but once upon a time we thought Google was different . We snarfed up eNom registered Google Apps domains - I have 7 of and use 3 every day including kateva.org. Despite the blood and spells and yada yada Google lifted a claw and let us keep the free domains even after they ended the program.
It was all quite easy -- but now Google Checkout is gone, and we can't use Google Wallet to pay for those eNOM registrations . So we have to go to every ... single... Google Apps account and enter our credit card information.
I just finished the 7. If I used Clark Goble's beloved Keyboard Maestro it would have been faster.
It wasn't entirely a wasted exercise. I'd set some of those domains up with what is today a laughably hackable password. They've probably been doing unspeakable things while I was away (though the pw still worked). They now all have 20+ character random string passwords that are almost as hard to type as they are to hack (don't even think of 'tap'). They also have new recovery and security alert features.
I'll gradually move the eNOM domains over to my Dreamhost account; I like Dreamhost as a registrar and that way I'll only have to update my credit card once.
- fn -
 I'm grandfathered into the very cheap $20/year rate. Google hiked prices after that.
 I'm not sure what Google Wallet is, but it's not intended for payments for online goods and services -- where it once acted as an intermediary between my credit card and merchants. It seems to be for mobile and in-person payments. I don't know where Google is going with this, but I don't care either.
 Even in 2009 they were changing ...
 The Google Apps charges are $0.00 monthly.
 Seems I was the only one. It worked well for me, but I guess now there's only Amazon.