The £200 extension can be the expensive option. Here's how to decide.

You buy an extension because it looks cheaper than custom development. Then your agency adds a connector, rewrites the frontend and patches a pricing rule. The licence was £200; the implementation was not.

That is an illustrative price, not a quote. The point is the decision: compare the complete cost of a working, maintainable process. An extension is often the right answer for a common requirement. Custom development earns its place when your business rules or integrations are the part existing modules cannot handle.

Write the difficult requirement first

“We need customer approval” sounds straightforward. “Trade applicants must wait for approval, guest checkout must be unavailable and prices must remain private” is three requirements. An account approval module may solve only the first.

Write five acceptance tests before researching products. Include the normal journey, the exception, the required integration, the relevant customer group and the recovery path. This stops a long feature list from distracting you from the missing feature that matters.

For an example of those boundaries, see customer account approval for a trade store.

Compare three years of responsibility

Use your own planning horizon and costs. Include recurring manual work the software leaves behind. A cheaper licence that needs an employee to repair data weekly may have a higher operating cost.

A ready-made module is strongest when the workflow is ordinary

Product attachments, stock alerts and common bulk catalogue actions are good candidates to assess before building from scratch. Look for product documentation, an admin demo, explicit limits, supported Magento versions and the theme and checkout you use.

Ask how updates are delivered and what your licence covers. Read the actual CommerceGears licence terms if you are evaluating our modules; do not rely on an article's shorthand for your entitlement.

Test the module with your data on staging. A marketplace listing or compatibility badge does not establish that it cooperates with your pricing, inventory and checkout extensions.

Custom development is strongest when the rule is yours

A bespoke supplier integration, unusual allocation rule or contract-specific ordering process can justify custom work. Make ownership, repository access, documentation and upgrade responsibility part of the agreement.

Require a handover another developer can use: installation instructions, configuration, tests for critical rules, a changelog and a known deployment process. Avoid treating code delivery as maintenance provision.

The useful middle option is often a standard extension plus a small, separate integration module. Keep adaptations outside vendor files so updates do not silently overwrite them. Adobe's plugin documentation describes one extension mechanism; the right technique depends on the requirement.

Make the buying decision reviewable

Take the shortlisted module's demo through your five tests. Mark each as pass, gap or unverified. Price the gaps before purchasing. If the core requirement remains unverified, ask the vendor to demonstrate it or treat it as a risk.

Browse our Magento extensions for the common part of your requirement. Send us the tests, Magento version, theme, checkout and integrations. A specific gap produces a useful answer; “can it do everything?” rarely does.