Mine are much cheaper to run because I chose a brand used in many offices.
From time to time an office throws out their stock of date-expired toner and drums, and the man who clears the stationery cupboard puts them on ebay. Sometimes they buy a new load of printers and chuck out still-current stock. I buy them for next to nothing.
These small office machines have a life expectancy of hundreds of thousands of pages, because they are designed to service a workgroup of office workers, or sometimes just a manager's office for privacy.
The smallest size cartridge for mine is rated at 3,500 pages, and the largest at 12,000
On ebay I can pay £5 to £30
The smallest one is ample for home use.
Colour ones are dearer and more complicated, and only good enough for colour charts and text, so I use mono.