Using inkjet refills enables people to save lots of money simply because they are so much cheaper than buying a brand new cartridge each time they run out of ink.  You can refill toner in all sorts of devices from laset printers, right through to many fax and photocopiers.   If you use a quality replacement there is no difference in print quality or performance between a refilled laser cartridge and a brand new replacement one.  The difference you will notice is the one on your pocket and the impact on the environment. The printer companies or those who sell new toner cartidges don’t like it obviously and will regail you with false tales of damamged printers or reduced print quality.

If you are just conecerned about the costs of purchasing replacement toner and keeping your expensive printer going then the savings will vary depending on the printer.  I usually buy a kit designed for my specific printer then you get all you need and full instructions however you coudl put the components together yourself.  Even with a ready made kit I generally would save around 70% of the cost of buying new toner cartridges and I get to feel a little better carbon wise too !