They don't say anything about tracks, rollers, idlers or sprockets...the pads look new or close to new. But the potential purchaser better take a close look, rather than assume.
* I guess it depends on what the potential purchaser has in mind for it. What does the same money purchase on the (newer equipment) used market?
* Good point on fixing: if it has to run, even when its broke down, today's wrench guys may be kind of lost without their computers. If it can sit for a while, well, not so important.
*Parts will be getting scarce--How long has it been since the last 977 rolled off the line?
*What is considered a more productive modern machine? A 300-series trackhoe?
*I was facing the same dilemma (but not with a like-new 977 looking at me!) on my little stump ranch. Wanting to clear more land for fields; more time than money; up here in Canukistan, hoes pretty well have buried track loaders. JD 450's are about all you see. I found a 30 year old Hyundai 290-with a thumb. It will do most anything a track loader will do and the thumb is a lightweight equivalent of a clam (4-in-1) bucket. (Those that everyone loves to hate because they are heavy and break easily.) What I don't like about the big hoe is that it is slow to move. (doesn't help that one of the travel motors is tired.) And with a hoe, it can change personalities by changing what you have on the end of the stick--wide cleanup bucket, hydraulic hammer, compactor, screening bucket, brush cutter, feller-buncher, stump grinder, etc...
*but, gul-darn it, I would still like to play with a big track loader!!
Jon.