Which AI Should We Pay For? · Lesson 3 of 4

Do the math for your headcount

10 minutes. Turn "$20 a user" into the real number on your card each month.

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Per-seat prices are designed to sound small. $20 a user is nothing. Then you multiply by 20 people, pick monthly billing because it feels safer, and the number is $500 a month, $6,000 a year. That might be a great deal. It might be $4,000 more than you needed to spend.

This lesson gets you the real number. Two steps: decide who actually needs a paid seat, then multiply.

Not everyone needs a paid seat. Go down your staff list and put each person in one group:

• Daily. They write, summarize, estimate, plan or answer email for a good part of the day. They'd use an AI assistant several times a week on real work. These people get a paid seat.
• Sometimes. They'd use it now and then: a tricky email, a summary of a long document. These people use the AI that's already included (Copilot Chat on Microsoft 365, Gemini on Google Workspace). If you have no included AI, they wait for the 60-day review.
• Rarely or never. Their work doesn't run through a keyboard much. No seat. They can still use the included AI if they want to.

Be honest, not hopeful. "They should use it more" is not a reason to buy a seat today. You can always add seats later. On annual plans, removing seats mid-term is usually harder.

Lee sorted Northgate's 20 people:

• Daily (5): Pat, Lee, both estimators, the project manager
• Sometimes (1): the bookkeeper
• Rarely (14): the electricians, who'll keep Copilot Chat on their phones for the occasional question

Here's the monthly cost at three headcounts, using prices as of October 10, 2026. Check the current price before you buy.

Seat-based options: you pay only for the people who get a seat

| Paid seats | Claude Team or ChatGPT Business, paid yearly ($20) | Claude Team or ChatGPT Business, paid monthly ($25) | Copilot Business add-on, list ($21, paid yearly) | Copilot Business add-on, first-year promo ($18) | Copilot Business add-on, monthly billing ($25.20) | |---|---|---|---|---|---| | 5 | $100 | $125 | $105 | $90 | $126 | | 10 | $200 | $250 | $210 | $180 | $252 | | 20 | $400 | $500 | $420 | $360 | $504 |

These are standard seats. A premium seat on Claude Team or ChatGPT Business is $100 a month paid yearly, so one premium seat costs as much as five standard ones. The Copilot add-on also requires that each person already has a Microsoft 365 Business license, which you're already paying for. The $18 promotional price applies to the first year only, on annual terms bought by December 31, 2026.

Plan-based options: the cost is the difference, for everyone on the plan

| People on the plan | Microsoft 365 Business Standard to Standard with Copilot (+$9.50) | Business Premium to Premium with Copilot (+$10.00) | Google Workspace Starter to Standard, 1-year commitment (+$7.00) | Google Workspace Starter to Standard, flexible (+$8.40) | |---|---|---|---|---| | 5 | +$47.50 | +$50 | +$35 | +$42 | | 10 | +$95 | +$100 | +$70 | +$84 | | 20 | +$190 | +$200 | +$140 | +$168 |

These are the extra amounts on top of what you already pay, using yearly prices for Microsoft. If you're already on Google Business Standard or Plus, your extra cost for Gemini is $0. You have it.

Yearly versus monthly

Paying yearly saves about 20% on Claude and ChatGPT ($20 versus $25), and Google says its 1-year commitment saves 16%. The trade is flexibility. A monthly plan lets you walk away after the first month. A yearly plan locks in the seats.

A sensible pattern: start monthly for the first 60 days, then switch to yearly for the seats that proved themselves. You'll pay a little more for two months, and you'll only commit to seats people actually use. (The Copilot Business add-on is different: Microsoft says it always needs an annual commitment, even with monthly billing. Check the terms before you buy.)

Whatever you choose, adopt this rule on day one:

> Company work goes in a company AI account. One account, owned by the business, for everyone.

That means:

• No personal accounts for company information. Not free ones, not paid ones. Personal plans can use chats for training by default. Business plans don't.
• The company pays. Stop the expense reports for personal AI subscriptions. Cancel them once the business account is live.
• The company controls access. When someone leaves, you remove their seat, and the work they saved stays with the business.
• One assistant per person, not two. Don't pay for Claude and ChatGPT and Copilot for the same person "to compare." Pick one now. Let the 60-day review make the case for a second, if there is one.

The rule also makes the math honest. Add up what you found in Lesson 1, Step 3. Northgate's estimator was paying $20 a month for ChatGPT Plus. That cost goes away when he moves to the company account.

Lee ran the numbers for Northgate's 5 daily users:

| Option | Monthly | First year | |---|---|---| | Copilot Business add-on, 5 seats, promo price | $90 | $1,080 | | Claude Team, 5 standard seats, yearly | $100 | $1,200 | | ChatGPT Business, 5 standard seats, yearly | $100 | $1,200 | | Business Standard with Copilot, all 20 people | +$190 | +$2,280 |

Everyone at Northgate keeps the included Copilot Chat for free either way. The bundle gives all 20 people full Copilot, but 14 of them are rarely at a keyboard. So the real choice was among the three 5-seat options, about $90 to $100 a month. A much smaller number than "AI for 20 people," and a much easier one to approve.

Open the Seat-Count Calculator and fill in Parts 3 and 4:

• Put every person in Daily, Sometimes or Rarely
• Count your Daily people. That's your seat count.
• Work out the monthly and first-year cost for each option still on your list, yearly and monthly
• Add any personal AI subscriptions that will be cancelled

Check it worked

• Every person on your staff is in one of the three groups.
• Your seat count is the Daily group, not your total headcount.
• You have a monthly and first-year cost for each realistic option, using today's prices from the vendor pages.
• You've written the "one company account" rule where your team will see it.

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Next: pick one, write it on one page, and set the date you'll check whether it worked.

→ Lesson 4: Decide, write it down, set a 60-day review

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