Nobody budgets for toner accurately. Not because the math is hard, but because the number on the cartridge is the smallest part of it.
Cost per page is an estimate dressed as a fact
Cartridge yields are published at 5% page coverage. That is a sparse page, a memo, a plain letter. Your actual documents have letterheads, logos, tables, charts and bolded headers, and coverage climbs fast. A marketing team running at 15% coverage burns through a cartridge in roughly a third of the pages the box promised.
Two more things quietly move the number:
Yield estimates assume ideal conditions. Heat, humidity and how the cartridges are stored all reduce real-world output. A stockroom near a loading dock is not ideal conditions.
Cartridges get replaced before they are empty. Machines call for a replacement with usable toner still in the cartridge, which is thrown away with it. You paid for it either way.
The costs that never make it onto a toner invoice
Somebody's time. Checking levels, working out which cartridge fits which machine, comparing yields, placing the order, receiving it, storing it. Two hours a month of an administrator's time is a real annual figure, and it never gets attributed to printing.
Emergency purchases. Running dry on a Thursday afternoon before a Friday deadline means somebody drives to an office supply store and pays retail. Every office does this a few times a year and nobody tracks it.
Reprints. Third-party cartridges vary. When output looks wrong on something a client sees, it gets printed again, and that page cost twice.
Capital sitting on a shelf. Bulk orders get better unit pricing and tie up money in a supply closet.
What flat rate actually changes
On our leases, toner is included and shipped before you run out. Not discounted, not billed per cartridge. Included.
The practical effect is not that toner became free. It is that four separate uncertainties collapsed into one number you already knew. High-coverage months cost the same as light ones. Nobody places an order. Nobody drives to a store on Thursday. Nobody prices cartridges.
Black and white leasing starts at $150 a month and color at $225, both covering up to 5,000 pages, with toner, parts, labor, every service call, delivery and installation inside that figure. Unused pages roll over. Paper is yours, and so is Illinois sales and use tax.
When per-cartridge buying is the better answer
If you own your machine, print modestly, and rarely call for service, buying toner as you need it may well cost you less than an all-inclusive rate priced around a machine that gets used hard. We would rather say that here than pretend otherwise. We sell genuine Canon toner, and you are free to buy elsewhere on a machine you own.
The flat rate earns its money when the copier is central to how the office runs.
Worth doing before you decide
Pull twelve months of supply invoices and add them to your equipment and service costs. Most offices have never seen those three numbers in one place, and the total is usually larger than expected. Then compare it to a single monthly figure.