What to look for???

Fellas, I want to buy a WWII USMC fighting knife for my son. I found a real nice one for $125.00 and of course the shop keep says it's real but it does look really nice, maybe too nice to be an original. I did not have a camera to take pictures but if I could get an idea what to look for I would really appreciate it. TIA

read the links on US Military Knives Bayonets Machetes as the real knives are considerably more than 125, that woudl be a modern copy

I see well used examples in the $125 range, some even less so if it is in really nice shape for that price, I'd look it over very carefully.