A customer asks for one small clip. The material is worth eleven cents. The print takes nine minutes. Your calculator says €0.94 and you charge €15, and you feel slightly guilty about it.
You should not. Here is the arithmetic.
What the small job actually costs
Setting up the job: a minute or two of someone’s attention. Taking the plate out, getting the part off it, pulling any supports, looking at it, bagging it, labelling it: five minutes if everything goes well. Putting it somewhere it will be found. Packing it. Answering the e-mail asking where it is.
That is fifteen to twenty minutes of a person, on a part whose material cost is eleven cents. At any plausible labour rate, the arithmetic price - before margin - is somewhere north of €10.
The nine minutes of machine time were never the cost. They never are, on small parts.
Three floors, not one
“Minimum order value” is usually one number, which is too blunt. There are three distinct things you might want to protect, and they behave differently:
A per-part floor. No single part quotes below this, whatever it is. Protects against the tiny part that still has to be handled individually. Note that this one multiplies: ten tiny parts at a €3 floor is €30, which is correct, because they each have to be picked up.
A per-line floor. No line - one part, whatever the quantity - quotes below this. Protects the job set-up. Does not multiply with quantity, which is the difference from the above.
A per-order floor. No order at all below this. Protects packing, admin and the conversation. This one is usually a small-order fee rather than a floor, so the buyer can see that ordering a bit more makes it go away - which is what you want them to do.
Most shops need the line floor and the order fee. The per-part floor matters most for very small parts in quantity.
Explain it, do not hide it
The way to charge a minimum without it feeling arbitrary is to show it as its own line. “Minimum order charge, €12.00” reads as a policy. A quote that silently comes out at €15 for eleven cents of plastic reads as a made-up number, and buyers argue with made-up numbers.
It also gives the buyer the information to act on: they can see that adding more parts absorbs it.
The one that catches people out
Your floor interacts with your quantity breaks. If the floor applies before the discount, a batch can end up at the floor price when it should not be. If it applies after, a discount can take a job below a price you said you would never go below.
Decide which you mean, and check it with a real part. This is exactly what a simulator is for: pin the awkward jobs - the tiny clip, the batch of fifty, the one big part - and look at all three before you publish a change.
What to set them to
Work out what fifteen to twenty minutes of your own time is worth, add the packaging, and start there. Then look at a month of orders you actually took and ask which of them you would rather not have had. That is usually the clearest answer you will get.
How floors and quantity breaks work together →
Quotometry prices every part from your own machines and rates, on your website, in seconds.