Make a three-bullet payback case for a software purchase

About this exercise

The finance committee wants a short case for buying invoice-scanning software. Write exactly 3 bullets labeled "Cost:", "Savings:" and "Payback:", with the math shown on each (payback months = first-year cost / monthly savings), under 60 words, plain text. Use the vendor's revised quote and only the savings the team measured, not the vendor's claim. Write a prompt that gets you exactly that.

Common mistakes when you ask AI for this

• No fixed shape. The AI writes a mini-memo with an intro, risks and a recommendation. Try: Be exact: "Exactly 3 bullets: Cost:, Savings:, Payback:."
• Trusting the AI to count words. AI is bad at counting. Ask for "under 60 words" and it often lands well over. Try: Cap each part instead: "each bullet under 16 words."
• Using the first quote. The original $14,400 fee comes first, and the AI may add setup to it. Try: Add: "Use the revised Oct 20 quote: $12,000 + $2,400 setup."
• Trusting the sales deck. "80 hours a month" is a bigger number, so the AI uses it. Try: Add: "Use our measured 40 hours, not the vendor's claim."
• Not showing the math. The AI states "payback in about a year" without the division. Try: Add: "Show payback as first-year cost / monthly savings."

What a strong prompt includes

• Labels the bullets
• Uses the revised quote
• Uses measured savings
• Shows the math
• Sets a word limit

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