The guys have said everything I would. my Quist luft was priced at $400 but the liner was damaged with blood so talked the guy ( a friend who works at a military surplus store) down to $300
I'd say $400-$450 is a fair price fr this one. The decal looks to be in pretty good shape. Do you know the size? Looks like a Q62 or 64.
Also, welcome to the forum