Let's see.
2018 Trek Project One Procaliber
$8,800 including computer and other bits
$2,100 for wheels to replace destroyed DTSwiss set
$1000 for new drivetrains, brakes etc
Strava says I've recorded 1,768 activities since I bought it. Much like Duck I commute and this is effectively my only bike. In the whole time I've had it I've used my roadie for two weeks while my fork was being warrantied, and maybe three times other than that. So let's says 1750.
So that works out to around $6.80 per ride. Thought it would be better than that by now
The first frame had 14,980 km on it, this frame has 19,099 km, 34,079 km total, making it $0.35 per km