I am a games collector.
Recently I bought random Steam key, and tried to activate it on my account via helper bot I made.
I received "AlreadyPurchased" result, but package id in response does not match package I own for this game (I own 79549, and failed to redeem key with 80925).
I'm interested, in which cases Steam considers I already have this product?
Is it compare app ids, or depots ids in packages, or something another?
What if I want to own two packages with one game?
For example, Call of Duty: Modern Warfare 3, that present in store (12205) does not have depot with russian language. But russian retail CD version (11616) contains ONLY russian. What can I do, if I want all languages? Can I activate both packages in some way, if I buy keys in retail?
Thank's for answer.