The Ethernet phy is actually pretty expensive, especially compared to USB 1.0. The isolation transformers alone are $1. Of course you could skip the isolation l

The Ethernet phy is actually pretty expensive, especially compared to USB 1.0. The isolation transformers alone are $1. Of course you could skip the isolation like some backplanes do. The ID assignment for USB is pretty awful and so is the robustness - for larger products it seems Ethernet is on the rise again.