Machine price is a one-off. Cartridges are a cost you pay for as long as you own the machine, and they scale with success — the busier the service, the more they cost. Which means the cartridge number matters more the better things go.
The arithmetic is simple enough to do on a phone. What is missing is usually not the ability but the inputs, because one of them is being withheld.
The sum
- Cost per shotCartridge replacement price ÷ its rated shots.
- Consumable cost per sessionCost per shot × shots your practitioner expects to use per session.
- Compare against your priceWhat you intend to charge, minus consumable cost per session, minus your staff and room cost for that hour. What is left is what the service actually earns.
That final figure is the whole business case. If it is thin, no machine discount fixes it, because the discount is one-off and the consumable is forever.
Two inputs, two sources
You need the replacement price and rated shots from the supplier, in writing. You need expected shots per session from your practitioner working off the manufacturer's documentation — not from a supplier's estimate, which has an obvious direction of bias.
It gets worse as you get busier
This is the part that surprises people. A machine that is marginal per client is fine while it sits idle and painful once it is fully booked, because every additional client adds consumable cost at a margin that does not work.
- At 5 sessions a month, a bad cartridge cost is an annoyance.
- At 40 sessions a month, it is the difference between the machine funding your next hire and quietly not.
- And you cannot re-negotiate it later, because by then you own a machine that only takes their cartridges.
That last point is the real reason to do this before purchase rather than after. See the cartridge guide on compatibility and lock-in.
Two more things to price at the same time
- The cartridges you have not realised you need. Usually the body ones. Price them now, at the supplier's own written price, and add them to the quotation.
- Shelf life. If you plan to buy consumables in bulk to protect the unit price, ask whether they expire. A bulk saving on stock that expires is not a saving.
Then take the total into the three-year comparison. It is the only comparison between suppliers that means anything.
Frequently Asked Questions
What if the supplier won't give a cartridge price in writing?
Then you cannot complete the sum, which means you cannot evaluate the purchase. Treat that as a decision the supplier has made for you.
Is a machine with cheaper cartridges automatically better?
No - cartridge price is one row of the sum, alongside build quality, parts availability and service terms. It is just the row most likely to be missing.