In a recent private sale that I had a hand in, a 1972 Golden State Arms imported, NIB (unfired) 510-4 (AMT - no full auto, no bayonet mt., no grenade rings) with factory Wohler scope, QD mount and exceptionally figured (even for an AMT) French walnut furniture was transferred for "around" $14K.
A very, very rare gun, within a small number of very rare guns... in a group of
maybe 3,000 guns total. I thought it went a bit under value.
C