The version numbers are mostly irrelevant as afaik price per token doesn't change between versions.
https://en.wikipedia.org/wiki/Masterpiece
https://en.wikipedia.org/wiki/Sonnet
https://en.wikipedia.org/wiki/Haiku
They dropped the magnum from opus but you could still easily deduce the order of the models just from their names if you know the words.
The pricing is more complex but also easy, Opus > Sonnet > Haiku no matter how you tweak those variables.