The Springfield Armory SA-1 is a semi-automatic variant of the M60. Springfield combined surplus parts along with new manufactured parts and a new receiver to build these SA-1 guns. Just like the original M60, it is belt fed and chambered in 7.62x51mm NATO, but it fires from a closed bolt (to make the BATFE satisfied that it cannot be converted to a machine gun). I don’t know what they originally sold for, or how long they were manufactured, but now they sell for $9000 and upwards.
Thanks to MFirepower for sending us the photo.