If they were using a custom python pipeline for the statistical models, yeah, I could see this argument. But, like many of the Nixtla tools:

!conda install -c conda-forge statsforecast
import sf
sf.fit(Xzero, yzero)
yone = sf.predict(Xone)

This is a pretty common "marketing" post format from Nixtla. I think they make good tools and good points, so I'm not at all mad about it. They're providing a ready to use tool (StatsForecast) and making a great point about it's performance and cost vs the AWS alternative. Asking for the total cost of developing and maintaining statsforecast means you'd have to also account for the total cost and complexity of developing and maintaining AmazonForecast...