Get a £20 Texaco Fuel Voucher when you buy 2 or more of the same Samsung Laser Cartridges.
Offer by redemption only, the cheapest 'cartridge you can get to qualify for this offer is the Samsung CLT-W409S Waste Toner Bottle, Viking Number Q2N-CLTW409S at £7.69 each, buy 2 and add the VAT it comes to £17.69.
Sell the cartridges on a certain well known auction site and you should get a few litres of free fuel after the maths!!
This is even better if combining it with an order, that way postage is free too.