Price Per Part
Why does the price for a part vary so much when the quantities change? In other words, why might a single part cost $500 but the same part cost $20 for 50 pieces?
The reason is amortization. Whether it is a single part or 50 parts it will still take the same amount of time to setup the job on a CNC machine. The cost to setup the job gets included in the single part or amortized over 50 parts. The same goes with any 3D CAD modeling, CAM programming, specialty tooling, or QC inspection that is involved with manufacturing the part.
If secondary finishing is needed (anodize, powdercoat, etc.) by a third party then the same principals apply. Usually, finishers will have a minimum price amount for a single part or small lot. Once the quantities go up you will start to see the price per part go down.
Another factor that plays into cost is material. A material supplier is going to give a much better price (usually $/pound) for larger quantities versus a small piece of material.
Lastly, if the quantities are high enough for large production then we look into ways to increase throughput. This might be creating custom jigs or fixtures to reduce the cycle time per part. Sometimes a single part does become a production part. The knowledge from running the first part will always help us hone in the price if the quantities change.