Houps ... just got 507uxII nicely negociated .. I'll end thinking that this was cheap ..
507uxII price in France was 6K€, raised to 6.5K€ recently (last summer) due to part & shipment cost increase related to Covid.
I myself work in consumer electronics industry & we had to face 10 to 20% increase of our bill of material & shipment costs.
Seems Luxman limited the increase on 507uxII but took the opportunity of 507Z to pretend key technical changes to justify a higher price increase. This is a common way of doing.
Now I could not afford.