Well:
About the Sinnträchtigkeit the selected intermediate ring lengths of 10 and 16 mm could argue
The price, I think that's right
Example with the Leica Macro Elmarit 45 mm (from Panasonic for Lumix G)
With ZR 10 mm to reach image sections 14.2 to 78 mm
With ZR 16 mm to reach image sections 12.8 to 49 mm
With ZR 10 + 16 mm to reach cropping 11-30 mm
(ZR Without the lens reaches cropping of 17.3 -)
