On another thread recently about 7.62x39 ammo.. someone mentioned that possibly PSA is setting up to produce that caliber... One thing is certain - as popular as that item is - someone will step up and produce it for the marketplace in good quantities if other sources dry up... I wouldn't expect it to be as cheap as that surplus stuff though - not at all...
You might want to use the search feature about this - there's been a lot of info recently about this caliber ammo..