How much would my original KAbar from ww2 sell for?

Ok so my grandpa gave me the original KA bar usmc fighting knife from ww2 and i wanted to know if the company would buy it back from me. It’s over 70 years old.

No one is going to “buy it back” from you.

Pretty much everyone kept their Kabars and took them home with them, so there are quite a few of them.
Your Kabar would most likely have the value of any Kabar knife.
They are running anywhere from $13,00 to $50.00 on Ebay presently.

Union Cutlery whose trade mark was “KA-BAR” made a variation in WW2….probably sometime in 1943.
For some reason they made a knife that lacked the customary branch of service (USN or USMC) stamp and it’s my understanding that they sold these to both services.
There were two variations. #1 is marked with the early maker name which includes “OLEAN NY”.
It typically has a round blade tip end that you see when you look at the pommel (butt). #2 has the later maker name of just “KA-BAR” and typically has a rectangular blade tip end peened to the pommel.
That has a lot to do with the value.

Secondly….
What does the scabbard (sheath) look like? Is it marked? Do you even have the sheath?