I did negotiate server/colo/cloud prices, but I spent person-months of effort deconstructing what the right price was. I've never done that for a car.

I once interviewed for a CTO job at a major storage vendor, and in the discussion they said that most of their major customers successfully reverse-engineered prices, and that kept their margins down. I've heard that (over beers) from some server resellers, too.

What does this mean? Did they perfect the negotiating process? Did they figure out what your margins are, then demanded that you halve them?

The customers figured out the prices of the hardware: disks or flash, a way to connect them to a "server", the "server", the network that the "server" offers.