So before going to bed, I decided to check out the Dell Outlet website, not really expecting to find much at midnight.
A Dimension 5100c with 1gb RAM, 160gb disk, Pentium D 820 (that's dual-core 2.8ghz), CDRW/DVD combo drive and a 9-in-1 media reader built in.
Yeah, I know, it doesn't have a DVD+/-RW like I kind of wanted, nor does it have the ATI Radeon X600SE video card (which I would like; the built-in video is analog VGA out, whereas the ATI is DVI out), but it came in under $800. I can live with that.
As for something much older, I also just picked up a junky Elna Supermatic on eBay. No, it's not pretty. It does, however, have parts I need for my own much nicer Supermatic. It's got the bolt-on knee lever (which I've rarely seen available as a part, and then in the neighborhood of $40) and the parts tray that slides under the free-arm (oy, do I need that). If there are any items in the parts tray, that's even better. We'll see if there's anything besides what's in the picture included.
There is a possibility that the knee-lever won't be of any use on my machine; I've seen notes that speak of a "conversion" to use a foot pedal (which I've got), so it might not work.