Most B2B companies should buy, not build. The build/buy question shows up often in board meetings and rarely gets the right answer. Here is the framework for thinking about it — and the specific signals that suggest one path or the other.
For most B2B companies under 250 employees, the answer is "buy off-the-shelf and configure it for your needs." Claude Team + custom Projects gets you 95% of the value of a custom build at 5% of the cost.
The build/buy question becomes interesting only when one of three specific conditions is true.
1. You have proprietary data that creates competitive moat. If your business has unique data (proprietary customer behavior, unique workflow data, regulated information) that off-the-shelf AI cannot access, building can create real competitive advantage. Most companies overestimate how unique their data actually is.
2. Your workflows are so specific that off-the-shelf cannot model them. Very rare. Most B2B workflows are similar enough across companies that productized tools work fine. If you genuinely have unusual workflows, build can make sense.
3. Compliance requirements that off-the-shelf cannot meet. Healthcare HIPAA, government FedRAMP, certain financial services regulations. If off-the-shelf tools cannot meet your compliance bar, custom builds become necessary.
Custom AI build (working production tool): $50K-$250K for initial development. Ongoing $30K-$150K per year for maintenance and improvement.
Off-the-shelf with configuration: $5K-$30K first year all-in. Ongoing $3K-$15K per year.
For most B2B businesses the build path is 5-15x more expensive with marginal value gain. The companies that build well are typically those with $50M+ in revenue and engineering teams that already have AI capability.
See how much does an AI chatbot cost for adjacent build/buy economics.
A useful middle path: build a thin custom layer on top of Anthropic's or OpenAI's API. You get custom integrations and workflows specific to your business, but you do not have to build the AI model itself.
This costs typically $20K-$80K to build and gives you most of the customization benefit at a fraction of full-build cost. Best fit for $20M-$100M B2B companies with engineering capacity.