We all do the same mistake with our office printers – once we buy them we usually live from the starter toner kit as long as possible, and once the ink is finished, we’re searching for the long lost box with the manuals within it, and as with most papers within this day and age – it’s probably lost forever, together with the information within it. But don’t worry, we know how it is, and this is why we’re here today. We did the research for you and found the best option for your printer: Best buy option for the Lexmark XM3150 Toner Cartridge From my experience with Epson Inkjet printers, I can openly say that I’m thankful to Lexmark for making toner exchanges so simple and so rare. Most of the XM31 line of printers needs a refill maybe once every two years, and there is a good reason behind it – with most toners from Lexmark you can expect up to 35.000 pages printed out. And if you calculate the price of around $120 per toner cartridge, you end up with a price of 0.005 per piece of printed paper. And I don’t know about your office, but we exchange ours maybe every two to three years. With that said, always go for genuine ink, which in your case should be the Lexmark 24B6186 Black Toner Cartridge, which is currently priced at around $112 at Amazon within Lexmark’s official store. The same toner is compatible with the whole XM31 line, so regardless which model you have, if it starts with XM31 – then it’s compatible.