You buy a cheap colour inkjet printer (and we're talking <£40) and replacement ink cartridges cost more than printer, ink heads dry up and require constant cleaning, cartridges require constantly replacing and print costs per sheet are astronomic.
You wouldn't buy a diesel to do short journeys or cheap trainers to run marathons, cost implications of cheap inkjet printers are well documented, so who is being scammed?
Buy cheap, buy twice or in the case of inkjet cartridges, multiple times. Caveat emptor.