I watched a documentary a few months ago that looked at built-in obsolesence. Printers were one of the products targetted, and a bloke in Russia had apparently devised a software program that would reset the 'counter chip' in printers that renders them inoperative ...
There is a guy on ebay that does this for around a tenner from memory. Involves you pushing a combination of buttons on your printer to print out various reports which give him firmware and other useful details. You email these across to him. He then emails you back with a full instruction guide and a zip file which includes a new firmware exe file which resets the printer counter to zero and keeps it that way. You can then fill up your laser with a 3rd party toner. This generally involves drilling a small hole on the end or pulling off a plastic cover and pouring in the toner and covering the hole up again. Of course printer drums don't last forever but at least you will get a few years out of your laser without having to dump it since it is generally cheaper to buy a new printer than pay full whack for an OEM toner cartridge.