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The biggest cost driver is rarely the technology stack — it is almost always how much is still undecided. Each unanswered question in the requirements becomes a contingency inside the number you receive. A supplier that cannot see the exceptions difference between vue and react edge cases has to assume the more expensive option. Spending a week on a discovery phase frequently cuts the overall figure far more than negotiating the rate.
Integrations remain another reliable source of cost. A feature that touches only your own data is predictable; the same feature connected to an old accounting system is a different problem. The effort hides in the counterparty: rate limits and sandbox access, long certification processes, fields that mean something different on each side. Ask any vendor to price integrations separately, since this is the usual source of overruns.
Non-functional requirements quietly rewrite the estimate. An application used by a small internal dedicated team vs freelancer is a very different build from the same feature set serving thousands of external customers. Audit and compliance requirements, uptime targets, load handling, vue.js development traceability and accessibility all add real engineering time. Write them down at the start nearshore or offshore software development expect the estimate to move later.
Who actually does the work changes the arithmetic. An hourly rate says almost nothing on its own: a senior engineer at a premium rate frequently turns out to be cheaper per delivered feature than a pair of junior developers who require heavy code review. Check too which roles are billed: project management, QA, DevOps and analysis are legitimate costs, but these should be named rather than hidden inside a blended rate.
The quoted figure is never the total cost. Plan for cloud costs, paid APIs, logging and alerting and a maintenance allowance each year. A useful planning figure is that a live system requires a recurring percentage of the initial investment annually simply to stay current. Treating the launch as the finish line is the most common budgeting mistake.