The single largest cost driver is laravel better than wordpress not technology — it is uncertainty. Every ambiguity in the brief turns into a buffer somewhere in the quote. A supplier that has no visibility into the exceptions and build an mvp edge cases will assume the worst. Investing a few days in a proper discovery can cut the total far more than negotiating the rate.
Connections to other systems are the second big multiplier. A feature that touches only your own data is easy to estimate; the same functionality wired into an old accounting system is not. The unknown hides in the other system: undocumented APIs, long certification processes, inconsistent data. Ask the estimator to break integrations out as separate items, because this is the usual source of overruns.
Quality attributes can easily double the number. An application used by twenty people is a very different build from the same idea serving thousands of external customers. Audit and compliance requirements, high availability, performance under load, traceability and localisation all add real engineering time. Write them down at the start or expect them to arrive later as change requests.
The team you are quoted matters. An hourly rate tells you very little on its own: an experienced engineer at a premium rate can be less expensive in the end than two inexperienced developers who need supervision and rework. Ask as well which roles are billed: delivery management, QA, release engineering and difference between nearshore and offshore development design are real work, but they should be itemised.
The quoted figure is rarely what you will actually spend. Expect cloud costs, paid APIs, llm development company observability and an ongoing support budget each year. A reasonable rule of thumb says that any production system requires a noticeable fraction of the original budget per year simply to stay current. Treating the launch as the finish line remains the most frequent planning error.