Estimation question
Imagine you have developed a toothbrush that will last a lifetime for a user. How will you price it?
- Amazon
- Estimation
- Medium
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What this question tests
Business model and pricing reasoning: can you price a durable, repeat purchase eliminating product using lifetime value logic instead of a cost plus guess.
How to approach it
- Reframe the business problem: a lifetime toothbrush eliminates the recurring replacement purchase, so pricing must capture the value of all future purchases avoided, not just manufacturing cost.
- Estimate what a customer would otherwise spend, assume a replacement toothbrush every 3 months at 5 dollars, roughly 20 dollars per year, over an assumed 20 year usage horizon, about 400 dollars in avoided spend.
- Apply a reasonable discount so the customer still saves versus paying as they go, assume pricing at roughly 150 to 200 dollars, capturing a large share of lifetime value while remaining an attractive upfront deal.
- Consider manufacturing cost as a floor, assume durable materials cost more upfront, so the price must exceed cost plus margin, which a few hundred dollars comfortably covers.
- Consider a secondary model, a lower upfront price with a small annual maintenance or head replacement fee, to reduce sticker shock while still capturing recurring value.
- State the recommended price as a range, roughly 150 to 200 dollars for outright purchase, and name the assumptions this depends on.
What a strong answer includes
- Anchors pricing on customer lifetime avoided spend, not just production cost, which is the economically sound approach.
- States every assumption clearly, replacement frequency, price, and usage horizon, rather than jumping to a number.
- Proposes an alternative pricing model, upfront plus small fee, showing awareness of real purchase psychology.
Common mistakes
- Pricing based only on manufacturing cost plus a standard margin, ignoring the value of eliminated future purchases.
- Giving one number with no stated reasoning or assumptions.
Likely follow-up questions
- How would you price this differently as a subscription instead of a one time purchase?
- What would you do if customers balk at the high upfront price despite the long term savings?
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Learn the skill behind it
Chapters of the AI PM course that teach what this question tests.
- Chapter 2: Data fluency: SQL, logs, and reading the truth yourself
- Chapter 9: Prove it paid off: outcomes, economics, and pricing
- Chapter 14: Get the job: the AI PM interview loop