[JJ_SO]

But regardless, overall, APS-C is much cheaper than FF.

Lets examine that then?

One of the most prolific Fuji X-mount lenses is the 56mm f1.2 R. US price: $999.
FF equivalents:
Tamron SP 85mm f1.8 VC USD. US price: $749.
Canon EF 85mm f1.8 USM. US price: $420.
Nikkor AF-S 85mm f1.8 G. US price: $477.
Sony FE 85mm f1.8. US price: $598.

Hmmm...

Ok, I'll try again. 

One of the most prolific Canon EF-M lenses is the EF-M 22mm f2 STM. US price: $249.
FF equivalent:
Canon EF 40mm f2.8 STM. US price: $199.

Seems that FF equivalents are not more expensive, rather it looks like only slower APS-C lenses are cheaper than faster FF lenses.

We can go on: Single long tele zoom from 
Fuji 100-400: 1690.- CHF
Canon: 1870.- CHF
Sigma: 810.-
Tamron 750.-   (+tripodfoot with Arcaswiss socket: 150.-)

All two third party lenses are more practical than the Fuji, less heavy, more compact and at APS-C similar or better performing. Not to mention the superior customization.

Shall I go on with 150-600 range? Sigma sports is cheaper AND better than the Fujinon. MUCH better to customize while the Fujinon is ridiculously limited in critical aspects.

Wide angle zoom:

Fujinon 8-16/2.8: 2200.-
Sigma 12-24/4: 1540.-
Sigma 14-24/2.8: 1300.-
Nikon 14-24/2.8: 2300.-
Sony 12-24/4: 1660.-
Canon 11-24/4: 2750.-

All FF wideangles will give better detail if the right body is behind them. The Nikon will deliver more flare, but the Sigma already is much better. It's the alternatives existing for FF, but not (much - there's a bit Laowa and a tad Samyang MF glass) for Fujifilm. And although Fujinons are great, none of them is THAT great to do the impossible.

Standard zoom:
Fuji 18-55/2.8-4.0: 690.-
Nikon 24-85/3.5-4.5 (admittedly crap, but FF): 528.-
Canon 15-85/3.5-5.6: 650.- (including 50% more range)
Nikon 16-85/3.5-5.6: 690.- (including...)