Successfully estimating a proper budget is all about getting the right amount of funding, resources in place, and finding efficiencies where possible to deliver quality in your projects.
Project planning is a process, not just a one-time event. As the project evolves, the plan will need to evolve with it.
While there must always be room for human error, a key to running a successful project is not waiting for that error to happen.
Using an agile-inspired approach can lead to work that surprises all in involved for the better, but getting there doesn’t come cheap.