Looking at recent completed sales on GB The older pre ban Armscorp M14s seem to be selling in the $1350-$1500 range.
The more recent post ban Armscorp M14 NM rifles are selling in the $1725-1825 range.
In comparison Springfield Armory M1A in their standard and loaded grades can be had all day for $1550-$1700 new in the box.
Older Springfield Armory standard grade M1As will sell in the $1300-1500 range. Really early examples with all military parts will sell for more.
Springfield Armory National Match and Super Match M1As will sell in the $3000 range.
Which is to say the Armscorp M14 NM rifles selling on GB are over priced. There is nothing about the Armscorp rifles that is National Match despite the appropriated “NM” stamp on the receiver and the quality, while not bad, isn’t at the same level as a Springfield Armory rifle.
I’d price it in the $1200-1300 range and it would be fairly priced. However, you can obviously list it ion GB and get more, due to either the “M14” or “NM” stamp.