According to Google's docs (https://developer.android.com/training/in-app-billing/preparing-iab-app.html#GetSample) the Google Play Billing Library, required for in-app purchases and subscriptions, is obtained from the Android SDK Manager, in the Extras section.
In my Android SDK Manager Extras section, it only shows - 1) Android Support Libary, 2) Google Play services and 3) Intel x86 Emulator Accelerator.
I am rather sure that the Google Play services is NOT the Billing Library.
Let me mention that my Eclipse is v2.0.1.20130919-0803 and there is an update available. Also my SDK Tools are rev 22.3 and SDK Platform-tools are rev 19 (there are updates for both).
I would rather NOT get the updates at this time. Must I, in order to get the Billing Libaray?
Thanks Paul
From the very limited info I have found regarding my question, it seems that Yes, I have to get the updates. A couple of people have posted that other items do not appear in the SDK Manager when the latest versions of everything are not being used. I'll know more tomorrow, after doing the updates.
I did the updates (that's a story in itself) and now that my Eclipse is fully up to date, the Google Play Billing Library is listed under Extras in the Android SDK Manager.
So the answer to my original question is Yes, I needed to do the updates.