CWmike writes: 'There's a perception that [printer] ink is one of the most expensive substances in the world,' says Thom Brown, marketing manager at HP. Well, yeah, writes Robert Mitchell. One might get that feeling walking out of a store having spent $35 for a single ink cartridge that appears to contain fewer fluid ounces of product than a Heinz ketchup packet. Brown was ready to explain. He presented a series of PowerPoint slides aptly titled 'Why is printer ink so expensive?' I was ready for answers. The key point in a nutshell: Ink technology is expensive, and you pay for reliability and image quality. 'These liquids are completely different from a technology standpoint,' Brown says, adding that users concerned about cost per page can buy 'XL' ink cartridges from HP that last two to three times longer. (Competitors do the same). The message: You get value for the money. No getting around it though: Ink is still expensive, particularly if you have to use that ink jet printer for black and white text pages.