I've only purchased a Mahjongg game recently and it was in the $20-$30 range if I remember correctly.
I got it from our local Mac store (a privately owned store... not the Apple-owned store), so it was probably a bit more expensive than if I found it somewhere else.
I recently downloaded OPERA for a new browser and there are widgets available that are games.
This is how I got the old game, ASTEROIDS.
That's it for games on my mac.
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fides solus
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LIBRARIES... Hardware stores for the mind