When buying makes sense
For most organizations, using an existing AI product or API is the faster and cheaper path. An established vendor has already solved the hard engineering problems, absorbed the cost of training or fine-tuning a model, and built the infrastructure to run it reliably at scale. Buying makes the most sense when the problem you're solving isn't unique to your business, speed to value matters more than customization, and you don't have the in-house expertise to maintain a custom system over time.
The tradeoff is control. You're dependent on the vendor's roadmap, pricing changes, and uptime, and your data may need to leave your own systems to be processed. For many use cases that tradeoff is entirely reasonable, but it's worth naming explicitly rather than discovering it after the contract is signed.