no offense, but mostly matching parts - is that like almost pregnant?
If its mismatched, unless say the grips or maybe a firing pin, it is a shooter and shooter price and most people won't pay above say, $1,000 for a mismatched, but nice looking WW2 luger. And that depends on the shooter, not a collector, as some would pay full price for one with a mismatched firing pin, but the vast majority of folks wouldn't.
Again, no offense, but unless you told them it was mismatched, that sounds like prices a dealer would tell you and most dealers aren't luger guys, or they are always very high, case in point, there was a ratty 1910 for years at the shows in the Philly area for $3500 and their comment was, its a 1910!
Did they take it completely apart or just look it over?