From Google's spokesperson, quoted in the article: "This is a short-term, timely agreement to ensure we have bridge capacity to meet surging customer demand for our agent platform, Gemini Enterprise, which has been even higher than we expected."

Google wants a lot of compute sooner rather than later, and they're willing to pay a premium for speedy delivery of that compute. SpaceX has the capacity already built and ready to go. Hence the high price.