Can't tell much from the photo angle. The tracers without ID cannelures look like the older color code shade, 1950's vintage, but this statement doesn't mean they are factory or not. Again the angle of the photos limits conclusions. Black/Red tip colors look like the Russian 12.7 shades, API, but there's still a possibility of it being AP(HC)T from Canada, C44. There was a considerable amount of Russian 12.7 projectiles for sale on the internet in the last year. All those bullets went somewhere. Russian 12.7 API and C44 AP(HC)T have the same color code, but the shades of red and black the two calibers used was noticeably different. Photos of the side of the cartridge and photos of the headstamps would tell more, but considering the amount of ammo at hand, it's understandable that pix become a difficult task.
For factory ammo, assuming all actually is factory, $2.50 round is a little better than the best price currently available. Black box American Eagle has been available as cheap as $19.95/box of 10, but none are for sale at this price currently that I know of. Recoil Gun Works had 4:1 LC M33 Ball/M17 Tracer at the best price I know of at present, $2.65/round. You may encounter some individual seller who may have $2.50 or $2/round. But this all assumes Factory and a lot of ammo is for sale on the internet as "factory," only because of the headstamp, but that doesn't mean anything. Fired cases reloaded still have the same headstamp as when they were brand new. So I always take a claim of "factory" with a grain of salt till I see the rounds or supporting pix. (To me, "factory" means the round was loaded by the company whose name or code is on the headstamp.) "Reloaded," "Manufactured," "Remanufactured," etc. should price significantly less than "Factory." No more than $2/round. Projectile will determine just where that price lands.
Hope this helps some.