A dell Vostro (basic business machine) with close to those specs shouldn't be to hard to get for around $500 if you get it without the monitor. If they just need Email an web (this is the "close to" part), go with a 32-bit OS and 2GB or RAM.
I have a Vostro...fantastic machine! I would recommend it to anyone that was looking for a PC and didn't want to build it themselves. They are built to last and Dell is willing to stand behind them for a long time, especially if you pay for the option of an extended warranty...much longer than most companies. That was part of the reason why I bought a Vostro.
Avoid HP if at all possible (it never ends well), they tend to garbage up a machine with multimedia frills that break, and most of the parts are astronomically priced. I've yet to see an old one that somebody was still happy with (toaster level disposable).
I have owned both a HP consumer grade PC (Pavilion a847c from tigerdirect) and a business class one (dc7600sff from geeks.com) and I will agree with you as far as the consumer grade ones goes. Not a good experience and it died a horrible premature death due to inferior parts that were made of plastic when they should have been metal. Not only that, but their software bundle they force on everyone really stinks, they install hidden crap that should not be on a pc without the user's knowledge and can cause problems (outdated versions of Python), and the CD burner they included wouldn't work with any software other than the outdated demo they provided in their crappy bundle. It didn't come with OS and drivers disks and instead had a restore partition.
I have been happy with the business class machine though. I am not sure if it was HP's doing (probably not) but the included software bundle was a good one that actually made sense (OpenOffice, AVG free, CD Burner XP, VLC, etc), had OS & driver disks instead of a restore partition, the burner works with up to date versions of popular burning apps, and the parts that should be metal, are.
I have purchased from Geeks before. It looks like most of their stuff is refurbs, which in my opinion are too high priced for a slightly used computer as compared to a new one.
Yes, most of their stuff is refurbs, but they do also carry new stuff. My HP dc7600sff was not a refurb, was the same specs as this one
, except that it also came with XP Pro, a keyboard, mouse, speakers and was $150 (over 1 yr ago). I repeat...it was new, not a refurb. Very nice little machine that was much better than the $800 consumer grade piece of HP junk that I had, with similar CPU/RAM specs.