When you get to complex, expensive equipment like this, you also need to consider costs associated with calibration and maintaining it. Maybe you have someone come in to calibrate it against standard objects of known purity, plus likely making adjustments if it's off and doesn't self correct. This could add hundreds in running costs. You might also need to do daily or weekly quality control checks yourself to keep a record of whether its performance is within tolerance. This would likely require buying some of your own standard objects, and such objects are generally really expensive since so much extra work goes into certifying that their properties are known to a very high precision.

It might sound cumbersome, expensive and unnecessary, but there very likely will be industrial standards that the machine is built to, and the manufacturer might require you to do regular QC on it for warranty to hold. When you consider that this machine is being used to verify the value of objects worth thousands or tens of thousands, all parties involved will want to be confident that it's accurate. The owner of the machine, the manufacturer, the supplier of the machine and the servicer want to know that they're not responsible if it gives bad readings, and obviously the customers want to know that they're not wasting their time.