The use case matters more than the XR label.
A simple product visualization using existing 3D assets is a fundamentally different project from a multi-user training system with analytics, integrations and a managed device fleet.
3D content can be a major cost driver.
Clean source CAD or 3D assets reduce production effort. Missing models, complex environments or extensive animation can significantly increase content work.
Integration and operations belong in the budget.
APIs, user management, device deployment, support and updates are part of a production solution and should be considered from the start.
Interaction and quality assurance add complexity.
Physics, multiplayer functions, custom animation, precise tracking and multiple device targets all increase implementation and testing effort.
Hardware is only one part of total cost.
Charging, transport, hygiene, device management, replacement units and operational support may matter for training fleets and event deployments.
A reliable estimate needs a defined scope.
Target audience, core workflow, hardware, available 3D data, integrations and quality level should be clear enough to estimate. Open technical risks can often be reduced through a focused feasibility test.