It is called an analogy because it is not perfect. In a lot of ways used video game market is very analogous to the used book market. They both use the same basic business model, and have the same results, only the new book market uses it as advertising while the video game market wants to try to kill it. So, I don’t think it is terribly off base to compare the two.
To accurately compare video games to books, we would have to compare the total cost of creation of a single book versus a single game. That includes labor, fees, etc. Then we'd have to compare the price of a new book vs a new game. Then we'd have to compare the price of a used book vs a used game and whether used books are used in the same way.
We also have to realize that books have a lot of additional avenues such as schools purchasing them en-mass to be used as a study subject.
The problem with books vs games, is not that the analogy doesn't have some similarities, it is that the analogy is disastrously oversimplified to win an argument without actually looking at whether the details match up.
We would probably find out that while a game costs millions of dollars to create, a book does not. Yet a book sells for 10-20 dollars and most people want games to only cost them 30 dollars. And while the used model for books enforces a lot of "wear and tear" and people are more likely to want a book in good condition, video games don't really exhibit the same "wear and tear" since the actual content is either readable or not readable on the CD and most used locations will guarantee at least that.
In other words, books and games might follow the same structure, however video games are stressing that structure to the extreme and simply stating the structure works by bringing up books is disingenuous.
