[Brightcolours]

Now do the same comparison with Z 50mm f/1.8 and Z 24-70mm f/2.8 ;-)

Okay.

Sony/Zeiss Sonnar T 55mm f1.8 official Sony price: €1100,-
Nikkor Z 50mm f1.8 S official Nikon price: €679,-

Sony FE 24-70mm f2.8 GM : €2500,-
Nikkor Z 24-70mm f2.8 S : €2499,-

You forgot to mention the Sony FE 50mm f/1.8 ;-)

And in terms of street price, we are talking about 2050EUR for the Sony 24-70/2.8 and 2350EUR for the Nikkor.

The Z 35mm f/1.8 (800EUR) has no direct counterpart but the FE 28mm f/2 (400EUR) should have a comparable price tag - but obviously ...

The RF 85mm f/1.2 will cost 3000EUR - the Sony FE 85mm f/1.4 goes for 1700EUR at the moment. Sure, not comparable but that difference is not just a little there.

The FE 50mm f1.8 is NOT comparable to the Nikkor S, the SZ 55mm f1.8 is.

Sony FE 50mm f1.8 Sony price: €399,-
Canon EF 50mm f1.8 STM Canon price: €199,- (basically the SAME optical formula, the Sony having a built in adapter)
Nikkor AF-S 50mm f1.8 Nikon price: €279,-

With the Nikkor Z 24-70mm f2.8 S being brand new, not a very convincing argument to call Sony cheaper because some vendors have lowered the price a bit on the Sony lens. Same goes for comparing the 85mm f1.2 price when it is not even on the market yet and the Sony 85mm f1.4 lens which has its price slashed by some vendors. The Canon EF 85mm f1.4 L IS USM has a lower official Canon price than what you seem to have found for that older Sony,  and that Canon goes for €1497,-

The Canon RF 35mm f1.8 IS STM Macro has been priced by Canon for €499,-. The Sony FE 28mm f2 is priced by Sony for €480,-. The SonyZeiss FE 35mm f2.8 is priced by Sony for €950,-.