Hey all, this isn't really my arena so I'm hoping that somebody with some more knowledge can help me out.

I recently traded for an National Postal Meter M1 Carbine in very good condition with all matching numbers. The man I traded with said he received the rifle from his dad, who brought it back from France after World War 2. The gun is in very good shape, I don't have good pictures but I would say it's probably 90% or better. The bore is clean and sharp, and there are no real bad marks anywhere on the gun.

Basically, I have no idea where to start with this. I see some of these on Gun broker for 700, and some of these for 2500. Anybody have any insight? Thanks in advance!

You'd have to tell us what the markings are on just about every part to get a fair idea of where to start with pricing as a collectors item.

As a mixmaster shooter it seems $700 is about average for a beater nowadays.

Is an interesting thing I found for the M1 carbine.
http://www.instructables.com/id/HOW-TO-FILL-OUT-A-CARBINE-CLUB-DATA-SHEET-FOR-AN-M/

Pictures would help as well.

The rifle has the serial number stamped in more places than just the receiver?

There is a good chance that not all of the parts are NPM.  All of the companies making the carbines during the war shared their parts with the others to keep the production flowing.  Each major part is stamped with a manufacturing ID that lets you know which company made the part. The higher the percentage of NPM parts, the higher the perceived value.  If you decide to sell it, you will need to disassemble and photograph each part so the potential buyers can see the marking if you want to get the best price.

Nope. This is 'Murica not the rest of the world. Only the receiver will have the serial number. Various small parts most likely have s manufacturers code stamped on them. But sometimes not even that.

It was a comment on the ubiquitous "all numbers matching" that seems to pop up when describing a US martial arm. That the OP never came back tells a bit more.

Der....

Time to recalibrate the meter.

M1 carbines don't really have all matching numbers, they have matching types of parts. On the carbines several changes were made throughout production to the parts. To find out the value you need to see if it has all the correct type of parts for that year.
http://www.bavarianm1carbines.com/rifles.html

This website is excellent and will tell you if you have a mix of early and late parts, all early parts, all late, etc...