---
title: "The real cost of DIY AI inside a law firm"
url: https://notionforlawyers.com/post/real-cost-of-diy-ai-inside-law-firm
updated: 2026-10-17
author: Raghav Handa
---

# The real cost of DIY AI inside a law firm

The real cost of DIY AI in a law firm is rarely the subscription. It is the lawyer time spent building and testing prompts and workflows, the review of every output, the security and confidentiality assessment, the maintenance as tools change, and the risk if no one owns it. Count those before deciding whether to build or buy.

## Key takeaways

- Subscription fees are the smallest line; people time is the largest.
- Every DIY workflow needs an owner, a test routine and a review step.
- Security and confidentiality review is a cost even when the tool is free.
- DIY can still be right for narrow, low-risk tasks. Decide per workflow.

## The cost categories

| Cost | What it includes | Often forgotten? |
| --- | --- | --- |
| Build time | Designing prompts, connecting tools, trial and error | Yes |
| Testing | Running real examples and comparing to your own work | Yes |
| Review | Checking every output before use, forever | Yes |
| Security review | Reading data terms, deciding what may be entered, documenting it | Often |
| Training | Teaching colleagues and writing the policy | Often |
| Maintenance | Fixing workflows when models or products change | Yes |
| Failure cost | A wrong output reaching a client or court | Always |


## A simple way to estimate it

1. List the hours you expect to spend on build, testing and policy. Price them at your own opportunity cost, not a salary.
2. Estimate the weekly time saved after review, honestly.
3. Divide: how many weeks until savings repay the build? If it is more than a few months, reconsider.
4. Add an owner and a quarterly review date, or the workflow decays.

You can try the arithmetic with our calculators hub at /calculators, which includes tools for comparing practice-management costs. These calculators use your own inputs; we provide no benchmark figures.


## When DIY is a good idea

- The task is narrow and repeated, such as summarising your own meeting notes or drafting routine client emails.
- The data is low sensitivity, or the tool's terms clearly fit your duties.
- A lawyer will always read the output before it leaves the firm.
- You can describe the workflow in a page, so someone else could run it if you left.


## When to buy or keep it simple

If the workflow touches privileged material at volume, needs auditing or integrates with court or accounting systems, a vendor with proper contractual terms may be safer than a home-built chain of tools. Equally, many firms will find the best value in organising their matters and tasks cleanly first, because AI over messy data is expensive.

That is the thinking behind LawyerOS ($19 Starter or $39 Pro with AI, one-time): structured databases first, optional Notion AI use second. It is a template, so the firm still owns the supervision and policy.


## FAQ

### Is DIY AI cheaper than buying a legal AI product?

Not necessarily. The visible cost is lower but the build, review and maintenance time can exceed a vendor fee. Count your own hours.

### Who should own AI workflows in a small firm?

A named lawyer, with a written note of the workflow, its approved data and its review step.

### Do free tools have costs?

Yes: review time, data risk and possible changes to terms.

### How often should we review AI workflows?

At least quarterly, and whenever a tool or its terms change.