Just a rough estimate:
A quick VGChartz search says pokemon games have sold 181 million copies (33 games).
If each copy makes a profit of around $10 per copy that would be almost 2 billion dollars.
If each copy makes a profit of around $5 per copy, it would be 1 billion.
At $20 it would make 4 billion.
So I'd say somewhere inbetween 1 and 4 billion dollars, for the games. Merchandising and others... I don't even want to begin to estimate that.
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