I've ridden a lot of bikes. All but a scant few have been sold. Most sales are at a margin above my entire cost to acquire and assemble that bike. Profits are plowed back into project bikes, most of which are then sold. And so on. So, positive margins with a few exceptions, like a carbon road bike that I bought new and sold five years later. That one probably cost me $0.15 per mile ridden, net of sale.
My mountain bike must be one of the more expensive per mile, because it doesn't get the number of rides or the strict mileage of a comparable road bike.
I have a Chinese carbon bike that I built up last year. I ride it on special occasions. That one is probably still above $1.10 per mile.