Choose the process for the stage
There are two common wastes. One is machining metal at concept stage, then scrapping the design and realising the money only validated a shape nobody wants. The other is functional testing on printed parts, where the strength data cannot be used at all.
Each stage answers a different question and tolerates different cost and precision. Get it right and the budget goes where it moves a decision forward.
Rough trade-offs by stage
Concept wants speed and low cost. The shape is enough; precision and material can give way.
Appearance needs surface and colour that represent the final product; internal structure can be simplified.
Functional testing needs material close to production, or the data means nothing.
Engineering validation exists to expose production process problems early, not to make the part look better.
Pilot production demands stable process and batch-to-batch consistency. This is where fixing work holding and tool parameters starts to pay.
Not sure which stage you are at
Say in the enquiry what you are trying to answer — see the shape, show a customer, or run a drop test. Engineers will suggest a process on that basis rather than defaulting to the most expensive option.