It would be a nice starting point for a restoration, especially from a documentation viewpoint, but there are some pretty significant body issues that would be hard to correct while retaining original paint status. The driveline isn't in original condition, although the interior is reasonable. The rust on the underside of the hood as well as elsewhere, the rust throughs on the doors, and all the dings and dents on the rest of the body panels keep the car from presenting well, which is probably what is hurting the price. 130,000 miles is also fairly high without the car having been gone through.
Its also a 351-2V automatic, not the most desireable. To me, it would need to be restored to be worth showing or driving, leaving it in a garage as a survivor wouldn't do much for me, there are much nicer and more desirable survivors out there for reference. The cost of restoration wouldn't be cheap, at the end of the day you would end up with a nice '69 Mach, but value wouldn't be high because of the 351-2V/automatic, meaning it might not even be a good financial investment.
Carl