Disc or rim, why spend $8k+ on something that will depreciate by 75% in 3-4 years?
My S-Works Roubaix (2015 rim brake model with Ultegra groupset and c24 9000s) was listed on Facebook for over 4 weeks at $1800 before I bought it. 15.4-lbs after swapping to an 11-speed Sram groupset and carbon bars (also used Facebook finds). My more recent S-Works Diverge disc build cost more but still under $3k.
I do like the wider tire clearances of disc and added stiffness afforded by thru axle frames and hubs… everything else not so much. The extra weight of the Diverge isn’t so bad for gravel, but I'll always prefer climbing on lightweight rim builds.
More than one good point from ol' Harley