They are going for over 10k on secondary with full sets. Not sure where you're getting this information from...
Most peopoe probably doesn’t see any benifit with the 168000 compared to other references. If you want a more modern safir sub there is newer better references. If you want a more vintage feel and matte dial there is older ”better” references.
The 168000 is just an inbetweener I think!
I think the lack of a matte dial also hurts it. It's a bit too "modern" to get the bonus from the relative rarity
Hows about a 5513 with White gold surround? Last of the plexi but most people just want to have a matte dial
