Updated April 5, 2011. If you've got limited cash to burn but are still in the market for an excellent printer, there are still a lot of great options. This list of the best printers I've tested that are under (or almost under) $100 will give you some great printers to choose from (inkjet, photo, and even laser printers), even when money is tight. If you're looking for a great deal on a photo printer, try the Top Five Budget Photo Printers. Also check out the Top All-in-One Printers if you have a bit more to spend. There's also a list of the Best Wireless Printers and the my picks for overall Best Printers.
Brother's MFC-255CW is a very good color inkjet printer that is a great value at under $100. Like some other Brother all-in-ones I've tried, it has slow print speeds across a wireless network, but it scores high points for print quality--especially photos, which come out looking fantastic.
The Epson Workforce 30 is limited in functionality--you won't get a fax or scanner or copier in this almost-full-size unit--but it what it does, it does very well. In particular, photos look fantastic, in large measure thanks to the DuraBrite ink that Epson uses, but you won't sacrifice basic black-and-white quality either. For well under a hundred bucks (I've seen it as low as $39), this is a good deal.
Fantastically sharp and richly colored photos are typical for Canon printers, but for the price--under a hundred dollars--there was no reason to expect that pictures would look as good as they do from the Canon Selphy CP780. A Bluetooth adapter and battery are optional equipment (if you wanted both, you'd add about $130 onto the price) so it's not the kind of printer you can bring anywhere--but the price and the quality of the prints are both fantastic!
For the money (only about 50 bucks), it's hard to raise a complaint about this HP all-in-one printer. The Deskjet F4280 did an excellent job on black-and-white as well as color graphics, and photos look great as well. While it lacks a fax and is made for casual use only, it still performs as requested. For heavier use, though, the consumables (replacement inkjet tanks) might eliminate any initial cost savings.
For about a hundred bucks, you can hardly go wrong with the Pixma MP480 all-in-one--unless you intend to use it a lot. Then, you're likely to find that the options it lacks (an automatic document feeder, a paper tray) will make a more expensive all-in-one a better choice. And while it's advertised as a photo printer, it's not as portable as other photo printers in this price range, so decide what you're looking for and what you need before you buy.
The HP OfficeJet 4500 Wireless is not exactly a speed demon, but for the price (I've seen it below $129.99, and cheaper if you don't want wireless), it's a very good deal. For that price, built-in wireless, an automatic document feeder, fax, and (manual) duplex come as welcome surprises. Print quality for text documents was not the best I've seen, and duplex pages will bleed through, but color photos looked lush and wonderful.
An outstanding, low-end all-in-one printer from Canon--what else needs to be said? It retails for just over $100, so it doesn't exactly fit the category; but you get all the features you could want, plus the quality and dependability of Canon. Sure, the LCD is a bit small and it doesn't network, but nevertheless, this is certainly a best buy.