I think that the cost of Opus is already prohibitively expensive, so not sure how that would compare to Mythos. Check this calculator- it shows that a company with 100 devs can hit ~2.5M cost on tokens annually, which is wild! https://ai-cost-calculator.arnica.io
It's wild, but how many FLOPs in computation is occurring in those 2.5M in tokens doing? Might not sound quite as wild using that metric.
A 100 dev team is going to cost on the order of $25m a year (keep in mind cost is not just their salary, but also the HR/Management org to support a team of that size, benefits, office space, hardware/software). So if you think you get a 10% boost in productivity out of Opus, its not prohibitive at all.