Probably a bit too specialist to go hot but this is a great tip if you have a Samsung colour laser (Models: CLP-310, CLP-315, CLX3170 or CLX-3175).
These are excellent, compact printers but a set of four replacement toners from most retailers will come to more than £160. However, Amazon do all four in a set for £107.25 delivered (haven't seen the set anywhere else; claimed RRP £183.97). Still not cheap but a saving of over £50 every time. Makes these genuine Samsung toners cheaper than the aftermarket refills (when you can find them) and removes the risk of printer damage from leaky refills.
If you use them up at different rates you can still buy singles from time to time to even it out.
Hope this does someone a favour.