I'd dig it out by hand before I'd buy something like this, just too much to go wrong in my mind. IF you could work the machine a couple hours and start to get a feel for it, then maybe it would do OK for you. Take a look at the slop in the pins and bushings (how much does the backhoe swing side to side when you stop swinging) how much the bucket wiggles, how the cylinders and hoses look for rubber deterioration, scratched chrome on the rods, cracked rubber hoses.
Being a gas without a cab, IF it REALLY is from the 80's, it might not have had the hours put on it (like from a small town or cemetery) and the hoe might be tight enough to not drive you nuts. The regular tractor stuff applies, tires, engine etc. The big difference is the bigger/more expensive hydraulics, more hoses, more abuse than a farm tractor, hopefully a torque converter transmission. It probably won't climb a hill in road gear, you want it to spin the tires in low gears though.
Having a tractor already, I'd suggest a mini excavator, or better yet, pay somebody to dig out the basement wall, then backfill on your own.
