Best computer and all in one printer for the price?

My grandfather informed me recently that he was going to be looking for a new computer, so I did as any good granddaughter would, got online and started doing some research. I am currently in school for information technology, and do all of my education online, so I know a little, at least. I have only really worked with dell computers in the past, and as far as buying brand new, I figure that Best Buy is a good store and they a Dell desktop on sale this week for $549. I looked it over a little, it has 4gb of ram and a good processor and 6 high speed usb ports, and an hdmi port that will make my grandfather happy. Is this a good deal? Also, if you buy the computer they will give you a special on a printer. Is it a smart choice to want an all in one printer, that uses only 1 cartridge instead of about 5? And do you know which brands offer those types?