Price the operating path, not the connector label
Two projects described as a POS integration can have very different scope. One may copy a nightly inventory snapshot for a focused catalog. Another may require near-real-time product, order, payment, refund, customer, tax, and fulfillment behavior across several locations.
Begin with a diagram of the events and decisions the business expects to work. That exposes the records, timing, ownership, and exception states that determine implementation and testing effort.
Identify the main cost drivers
Complexity increases when source data is inconsistent, vendor access is limited, bidirectional updates are required, or the business needs custom rules that native products do not support. Security review, historical migration, staff training, monitoring, and ongoing support also belong in the estimate.
- Number and quality of source systems
- One-way synchronization versus bidirectional workflow
- Batch updates versus event-driven behavior
- Catalog cleanup and record matching
- Refund, cancellation, substitution, and recovery paths
- Authentication, permissions, privacy, and audit requirements
- Acceptance testing, rollout, monitoring, and support
Ask for a phased estimate with evidence
A useful proposal separates discovery, first operating path, optional extensions, and recurring services. It should state assumptions, exclusions, client responsibilities, acceptance checks, and what happens when a vendor API or source record does not behave as expected.
If the business cannot yet describe a dependable first path, fund a small discovery engagement before committing to a broad implementation. That replaces speculative pricing with a reviewed scope and testable boundary.