The reported deal between Apple and Google for the model now powering Siri was estimated at roughly a billion dollars a year.
The figure makes sense when compared with what competitors spend building their own capacity. Companies of similar size announced tens or hundreds of billions in infrastructure investment over the semester, with returns diluted across years.
A billion a year in contract terms is expensive in absolute terms and cheap in relative ones: it buys frontier capacity without tying up capital in data centres, without competing for scarce memory, and without the risk of building for a model that ages.
What's paid in exchange is dependency, and here it's doubled: the supplier is a direct competitor, and the contracted layer is the most visible part of the product.
For operations of any size, the reasoning transfers. Building your own capacity only pays when volume is predictable and large; below that, contracting is cheaper and the risk to manage is a supplier rather than a construction project.