A home printer can cost less than a couple of replacement cartridges. That inversion is intentional, and it is the clearest consumer example of pricing a device against its supplies.
The device is the entry ticket
When a product requires a proprietary consumable, the manufacturer can price the hardware low to widen the installed base. Every additional printer in a home is a recurring cartridge customer.
The hardware price then functions as an acquisition cost rather than a profit center. Losing money on the unit is acceptable if the expected consumable spend exceeds the loss.
Starter cartridges shipped in the box are frequently partially filled for the same reason. The first refill arrives sooner, which brings the customer into the paying relationship earlier.
Why cartridges carry the margin
Consumable purchases are repeated, low-consideration and made under pressure, usually when something must be printed immediately. That is a favorable position from which to set a price.
Switching cost is high because the cartridge only fits one family of machines. Rejecting the price means replacing the printer, which most households will not do over a single refill.
The result is a pricing structure where the profitable product is the one nobody shops for carefully. The printer was shopped for carefully, which is why it is cheap.
Chips and firmware protect the model
Cartridges commonly contain a chip that authenticates the supply and reports levels. Authentication is what keeps third-party alternatives out, and the model depends on that exclusion.
Firmware updates can change how strictly authentication is enforced, which is why a printer that accepted an alternative cartridge may later refuse it. The behavior is a policy decision expressed in software.
Level reporting also affects when a cartridge is declared empty, and the declared point is not necessarily the physical one. That threshold is a commercial setting as much as a technical one.
Why subscription printing appeared
Charging by pages printed rather than by cartridge converts an unpredictable, resented purchase into a monthly line item. Predictable revenue is worth more to a manufacturer than occasional large sales.
It also removes the moment where a customer compares cartridge prices, because supply arrives automatically. The comparison that threatened the model is designed out.
For low-volume households the arithmetic can go either way, since unused pages are still paid for. For heavier users the per-page price is usually the more favorable structure.
Where the model breaks down
Tank-based printers, which are filled from bottles rather than cartridges, invert the pricing back. The hardware costs considerably more and the ink costs considerably less.
That format only makes sense above a certain print volume, because the higher entry price has to be recovered through cheaper pages. Below it, the cheap machine remains cheaper overall.
Deciding between the two is therefore a question about volume rather than about which printer is better. The honest comparison is cost per page across a realistic year of printing.