Could be a bargain or could be a bomb, where was it rebuilt ? Ring the shop, does it look clean or a bit tatty, RUST ?, has it a defect ? Engine number and chassis numbers OK, get a REVS check, is the oil clean, is the coolant clean, brake fluid, powersteering fluid, fan belts, look at the discs for cracks or major wear, does the inside smell, it might leak in the rain.
Only way to tell is have a good hard look and make some phone calls.
Good luck.