I think the fact that they're relatively cheap stems from a few factors:
1) - they're everywhere. They made something like 2.4 gazillion of them.
2) - they're old and need some attention. Most buyers lack the sick attraction to degrubbing a rusty hunk of metal that hasn't seen daylight in 35 years.
3) - the Craftsman brand hasn't exactly been a hallmark of unparalleled quality during the past several decades.
4) - the contractor style of saw is nearly obsolete. "Jobsite" saws are more portable, and "hybrid" saws are the new thing for most home shops. Dust collection, blade alignment, and the larger footprint of the external motor are the downside of the contractor style saws.
5) - those who really know woodworking and appreciate the quality of the old C-mans still shy away from the old Craftsman rip fences because they're a hassle to work with. Why buy an old saw for $100, spend $50 for new bearings / paint / electricals / belt, and search the hills for decent $200 used fence? There are too many good competitive options.
All that said, they'll cut wood with the rest of them. I just know i see a lot of them for $50 if they're in "garage fresh" condition. Maybe $100 if they've got that showroom gleem.
paulh