What is a Claude skill?

A folder of instructions, reference notes and small scripts that Claude loads when a task needs it. With this one installed, ask Claude whether to build, buy or rent a tool and it follows a fixed method instead of guessing.

Yes. It is shared under CC BY 4.0: you can use it, change it and share it, including at work, as long as you credit Road map ROI and link to the license (https://creativecommons.org/licenses/by/4.0/).

Does it send my numbers anywhere?

The calculator script makes no network calls: it has no imports and does plain arithmetic, and you can read it in the .zip. The skill's instructions are text that Claude reads inside your own account, under your account's settings.

Is this financial advice?

No. It explains general decision methods with invented examples. For tax or accounting treatment, ask your accountant.

Free Claude skills for software decisions

Teach Claude to answer "should we build it, buy it or rent it?" the way a careful product manager would. Free to download, free to share.

Product economics

Ask Claude about a software decision and it will:

Compare every real option: build it yourself, buy something ready-made, pay someone to build it, or rent a subscription.
Flag the costs older methods miss: security checks and backups for AI-built apps, usage fees, and yearly price rises. The sources are linked in the skill.
Count your own time as a cost, not as free.
Say where every number comes from: a quote, a pricing page, your records, or an estimate.
Do the math with a small calculator script, not in its head.
Give the answer first, then the reasons, then what would change the answer.

Download the skill (.zip)

Shared under CC BY 4.0. Not financial, tax or legal advice.

How to install it

In the Claude app or claude.ai

Download the .zip file above. Don't unzip it.
Check that code execution is on: Settings, then Capabilities, "Code execution and file creation". On a Team or Enterprise plan, an owner turns this on.
Go to Customize, then Skills (older versions: Settings, then Features), and choose Upload a skill.
Pick the .zip file, make sure the skill is switched on, then ask a question like the one below.

In Claude Code

Unzip the file.
Move the product-economics folder into ~/.claude/skills/ (for you) or into .claude/skills/ inside a project (for everyone on that project).
Start a new Claude Code session. The skill loads when a question needs it.
The calculator script needs Node.js 18 or newer. In the Claude app, Claude still follows the method even if it can't run the script.

Try it with a question like this

"I run a 6-person design studio and our projects live in spreadsheets. Should I build my own system with an AI tool, buy a ready-made template, or pay for a subscription like ClickUp? I bill clients $70 an hour."

Prefer to click instead of chat?

The same method runs as a free step-by-step calculator on this site. Start with build, buy or rent, or compare building with paying per person.

More skills are on the way: how to ask your team what a new tool must do, and how to write a one-page brief.