Buying the inkjet printer or inkjet MFP (multifunction printer) that is best suited to your budget should be simple. It's not--and the complication is the ink. Replenishing this vital fluid costs much more over time than the printer itself costs initially, yet unwary buyers often overlook that expense. To find the most economical printer over the long haul, you need to pay attention to ink-onomics--how much your printer's inks cost and how much ink you'll use.

The first law of ink-onomics: The cheaper the printer, the more expensive its inks. We've tracked the prices of 56 inkjet MFPs over the past two years, and the average cost per page for inks destined for a cheap printer (which we define as one costing less than $200) has consistently been higher than that for an expensive printer (one costing $200 or more).

But does that mean you should avoid cheap printers like the plague? Not necessarily. Here's where the math of ink-onomics gets complicated. Your best buy depends on what you print, how much you print, and how long you plan to keep your printer. A person who prints sparingly overall and seldom prints photos may find that a dirt-cheap printer yields big savings, even after factoring in the printer's sky-high replacement ink costs, simply because the person won't be replacing ink cartridges very often. Someone else, who has more-ambitious printing needs or a strong interest in photography, may find that a cheap printer's ink bills are lethal.

How Ink-onomics Works on Real Printers

To demonstrate how ink-onomics works with real printers, we've selected one cheap printer and one expensive printer, and crunched the numbers over three years to calculate how much each would cost two hypothetical users: a person who prints relatively little, and a person who prints a moderate amount.

Our sample cheap printer is the $70 Canon Pixma MG2120. Not surprisingly, its ink costs are high: 6.3 cents per page for plain text documents and 14 cents per page for color printouts.

Our sample expensive printer is the $300 HP Officejet Pro 8600 Plus e-All-in-One Printer. Its ink cost for black pages is just 1.6 cents per page; and for four-color pages, 7.2 cents per page.

For our hypothetical user with light printing needs, the cheap Canon printer makes economic sense, even after three years. The Pixma MG2120 costs so little initially that, despite its pricier inks, its first-year costs of $199 are significantly less than even the purchase price alone of the more-expensive HP Officejet Pro 8600 Plus. Three years after the initial purchase, the cheap printer's higher ink costs have ballooned to a total of $387--roughly 5.5 times the original price of the printer--but its total cost ($457) is still a little less than the expensive printer's total cost after three years ($478.83). A user with even lighter printing demands--say, 25 or 50 pages per month, along with a smattering of photos--would save even more with the Canon.

The picture changes dramatically, however, for the user who prints more frequently. At a medium volume of 250 pages of simple documents per month (175 plain-black text pages and 75 four-color pages) plus 25 4-by-6-inch color photos each month, the cheaper printer's ink costs mount quickly. By the end of the first year of use, the total cost of buying the cheaper printer and its costlier inks is $392.50, as against a total cost of $449.03 for the first year of the expensive printer and its cheaper inks. And three years after the initial purchase, the cheap Canon printer's total cost dwarfs that of the more expensive HP printer: $1037.50 to $747.08.

Our Printer Comparison Calculator

The general lesson is clear: If you print a little, a cheap printer can save you money. If you print a lot--or a moderate amount, as in our example--you should pay extra up-front for a more expensive printer. But if your printing usage falls somewhere between light and medium, or if you're considering two similarly priced choices, how do you decide which printer is the better buy? We've built a calculator to crunch the numbers for you.

To use our calculator, you'll need to supply some information about your printing habits and about the two printers you're considering.

The first step is to estimate how much you print each month in three categories: text documents (any printout that uses only black ink), color documents (such as presentations with graphics or charts), and 4-by-6-inch photos. Enter those figures into the cells to the right of each category name below.

The second step is to supply information about the printers you're considering. Start with the printers' purchase prices. Then identify how much the printers' black cartridges cost and how many pages they'll produce. Then list the same information for the printers' color cartridges. (Some printers use a single cartridge that includes all three kinds of color ink. Others use separate cartridges for cyan, magenta, and yellow; so enter the cost and page yield of one color cartridge, and tell the calculator whether the printer you're considering uses one cartridge or three. If the page yields for the three color cartridges differ, enter the average yield for all three cartridges.)

How do you determine the page yield of a printer cartridge? Most vendors provide ink pricing and page-yield information on their websites, somewhere between the printer's specs and the shopping page for ink. A few vendors, including Brother and Samsung, do not sell their supplies directly, and as a result you must shop around for the relevant pricing. Canon will happily sell you an ink cartridge but it buries the page-yield data in its vaguely named "Resources and Learning" section.

That's all the information you need to enter. Our calculator will figure out the cost per page for text documents, color documents, and photos, and then estimate the cost of that printer over periods of one, two, and three years.

A note for readers who are versed in total cost of ownership: These numbers do not account for the inks that come bundled with or loaded in the printer, nor the cost of paper. Remember, too, that the results from our calculator are necessarily estimates. Even documents of the same type will use different amounts of ink and end up costing different amounts, depending on the specific content they contain.

Other Considerations

Several other factors may drive up the cost of a printer in the long run. Here are three tips for saving money.

Beware of skimpy starter cartridges: Many printers ship with special cartridges that might be called "introductory," "ship-with," or "starter," and are usually not available for sale otherwise. These little beauties may look like their normal-size brethren, but in many instances their capacity is considerably smaller--so check before you buy. The difference between one printer's starter cartridge and another's can be quite significant. For instance, the Canon Pixma MG2120 comes with starter cartridges that promise yields of just 180 pages each. The HP Officejet Pro 8600 Plus, in contrast, ships with high-yield cartridges that the vendor says offer up to 1000 pages of black and 700 pages of each color--a nice bonus starting out.

Look for separate color cartridges: Some inexpensive inkjet printers (including the Canon Pixma MG2120) use a unified or tricolor cartridge--a single cartridge containing all three colors of ink. It's less of a hassle to transport and install, but when you run out of one color you must replace the entire cartridge--potentially wasting a lot of ink and thus increasing your cost per page. Buying a printer that uses separate cartridges for each color removes this risk. Avoiding tricolor-cartridge printers is especially important if you produce a lot of color output, especially photos.

Buy high-capacity cartridges: Some printers offer more than one size of cartridge. Usually the price per page drops considerably when you buy the highest-capacity cartridges available for a particular printer model. If your printer sees infrequent use, however, buying a huge cartridge is overkill--and may backfire if the cartridge clogs or dries out before you finish it.

Among the other factors relevant to buying a inkjet printer or inkjet MFP are features, quality of output, and speed. Consult PCWorld's ranked printer charts for assessments of the latest models. Before you buy, though, remember that a little work in ink-onomics now may proterct your wallet from serious injury later.