Build or Buy Ecommerce Search? Three-Year Cost Model
Compare the full cost of building or buying ecommerce search: engineering, infrastructure, data, merchandising, measurement and migration over three years.
Build or buy ecommerce search? A three-year cost model
Search ownership costs more than a licence or a cluster. Compare the work needed to launch, operate and improve the same experience over three years. Use your own staffing, traffic and supplier inputs, then test whether the decision changes under higher demand, slower implementation or more complex merchandising.
Compare equivalent services
A prototype and a production service are different cost objects. Write the requirements first: query types, languages, catalogue size, availability rules, peak traffic, relevance evaluation, reporting, merchandising controls and incident ownership. Score each option against the same requirements before comparing totals.
Building can be rational when search is a strategic capability, requirements are unusual and a team is funded to operate it. Buying can be rational when time, specialist capacity or dependable operation matters more than owning every component. A hybrid approach may keep the storefront and business policy in-house while outsourcing a bounded retrieval or ranking service.
Count work wherever it sits
Include initial engineering, product-data preparation, interface work, event instrumentation, migration and acceptance testing. For each subsequent year, include infrastructure or subscription charges, engineering maintenance, relevance work, merchandising operations, monitoring, support and evaluation.
Separate cash costs from internal time. An existing employee still has an opportunity cost, but it should not be counted again as an additional hire unless that hire is actually required. Likewise, do not charge the same shared platform team fully to multiple projects. Algolia's own build-or-buy discussion recognises the difference between basic retrieval and the work needed around it. Primary vendor perspective.
Use a transparent three-year calculation
Total cost equals initial implementation plus the sum of recurring costs in years one, two and three. Model annual usage explicitly instead of multiplying a launch-month invoice by the whole period. Record what a billable request includes, whether variants or languages change record counts, and how peak capacity is priced.
As a synthetic example, an option with £60,000 of initial work and recurring costs of £90,000, £100,000 and £110,000 totals £360,000. A second option with £25,000 upfront and £105,000 in each year totals £340,000. The £20,000 difference is a comparison of these invented inputs, not a PA quote or market benchmark.
Keep commercial benefit outside the cost total
Add a separate benefits scenario only when the inputs are defensible. A claimed conversion uplift should not cancel a known cost until its relevance to your traffic and catalogue has been tested. Record the evidence, expected ramp and uncertainty rather than presenting one optimistic outcome as a forecast.
Decide which assumption matters most
Vary engineering capacity, usage growth, launch delay and supplier charges. If a modest change reverses the decision, negotiate or test that assumption first. Ask the shortlisted suppliers for the same scope, usage units, service responsibilities and exit conditions. See how PA describes its pricing.
Illustrative example
Synthetic GBP, undiscounted, excluding tax: A upfront 60000; Y1 90000; Y2 100000; Y3 110000; total 360000. B upfront 25000; Y1=Y2=Y3=105000; total 340000. A minus B=20000. Figures are invented to explain arithmetic; neither is a PA or competitor quote.
Downloads
- search-tco-inputs.csv (illustrative template)
Sources
- How Pricing Works, checked 2026-10-25
- Algolia: AI Vector Search, Build or Buy?, checked 2026-10-25
How Particular Audience does it
Frequently asked questions
Is buying always cheaper than building?
No. The answer depends on requirements, available expertise, scale and the work included in each option. Compare equivalent production services and include operation, relevance improvement and change management. A low initial build cost can conceal substantial ongoing ownership.
Should we count existing staff costs?
Include allocated time as an opportunity cost, with an explicit basis such as hours and a loaded internal rate. Keep it separate from additional cash spend. Do not count the same employee as both a full new hire and an internal time allocation.
Can the model estimate revenue uplift?
Keep revenue or contribution scenarios separate from total cost. Enter a commercial improvement only with a stated assumption or relevant test evidence. The worksheet does not establish causal uplift or promise that an engine will pay for itself.