Hartley: Depending on the condition of that knife, it's absolutely worth that much money. It's a treasure. How about some pics?
MK-IIs of that vintage were going for half that about five years ago.
Is yours serrated? It's right on the edge of when they started offering that as an option in 1971. Prior to that, they were all plain edged, narrow wasp blades.
If you sight down the edge, you may notice that the blade is canted five degrees, towards the serial number side. If you got it in 1971, it's possible that it's one of those earlier pieces.
These knives were introduced in 1967.
Gary Armorhide was made until 1977.
They were all made of L6 until 1979.
Forged until 1972, hand ground after that until 1979.
There was also a variant called the Command that had a sharpened swedge with serrations instead of being fully double edged. Those aren't nearly as common as the MK-II.