Subtracting the noise from this thread, it was a pretty good related discussion Burning Shadows booster box is $400 while PSA 10 Rainbow Charizard is $2,500? - #54 by gildri
@gildri seems to have done a pretty data science-based analysis and highlights some of the important variables.
I think the ratio in this current thread is a bit simplistic and you’d get a similar order even without dividing by pack price.
For me, I think you could just sort the sets by pack price alone and buy boxes of the ones with the cheapest packs. That way you’re buying as close to the floor as possible. There is virtually no downside risk. Given enough time, every single Pokemon set in history ends up more expensive than it started off.