How Much Does Custom AI Development Cost?

Custom AI development costs anything from a few thousand dollars for a focused feature to millions for a platform programme. That range is useless on its own, so this post breaks the cost into its parts: the build, the data work, evaluation, model usage, and running it afterwards. If you know which parts your project needs, you can estimate it.

The five parts of an AI project budget

• Build: the application, integrations, user interface, and the AI workflow itself — retrieval, prompts, tools, and guardrails
• Data preparation: collecting, cleaning, permissioning, and chunking the documents or records the system will use
• Evaluation: a golden set of real questions with known-good answers, and automated checks that run before every change ships
• Model usage: per-token charges from model providers, which scale with traffic and with how much context each request sends
• Operations: hosting, monitoring, cost tracking, updates as models change, and someone accountable when it misbehaves

Most estimates only price the first line. The projects that disappoint usually under-invested in evaluation, which is what tells you whether a change made the system better or worse.

What makes one project cost more than another

• Messy or scattered data: PDFs, scans, permissions that differ per document, and systems without APIs
• Actions, not just answers: an agent that updates records or sends messages needs tool design, approvals, and audit trails
• Accuracy requirements: regulated domains need stricter evaluation, citations, and human review paths
• Integrations: each system the AI reads from or writes to adds build and test work
• Volume: high traffic makes model choice and routing matter, because usage becomes the biggest ongoing cost

Model usage: the cost that grows after launch

Model providers charge per token — per million input and output tokens — and prices differ a lot between models. A system that sends large amounts of context with every request, or that uses the most capable model for every task, can cost many times more to run than one that routes simple requests to cheaper models and only escalates hard ones. Ask for a per-feature cost estimate and a routing plan before launch, not after the first invoice.

Fixed price or time and materials?

AI work feels uncertain, so vendors often prefer hourly billing. That moves the risk to you. A better approach is a small fixed-price first phase that proves the hardest assumption — usually retrieval quality or data access — against a measured evaluation set, followed by fixed-price phases once the unknowns are known.

Questions to ask any AI development vendor

• How will we measure quality, and will the evaluation set be ours?
• What will this cost per month to run at our expected volume?
• Can we switch model providers without rebuilding?
• Where do our prompts, traces, and data live?
• What is fixed in the price, and what would change it?

Published ranges to compare against

ResoluteX publishes its prices. The Data & AI practice — RAG pipelines, agents, multi-model routing, and evaluation harnesses — runs as fixed-price sprints of $2.9k–$9.9k over 2–4 weeks, with retainers from $1.4k a month disclosed before you commit. Custom Build Sprints start with a discounted $990 Pilot Week, then a flat $1,500 per sprint week. The AI Architect on this site will match a described problem to a product or practice with a USD price range and a timeline.