OTOH CF is where the big market is for it now and for the visible future. People aren't going eBay shopping for cheap steel and aluminum frames or rims....and if they are--market forces typically mean those parts are overbuilt rather than underbuilt (because making metal parts lighter costs more money).

It is easy to demonstrate with a magnet whether a bike frame is steel or aluminum. You cannot prove that a carbon part is actually Toray T800 carbon fiber, you have to trust the seller...which, well, I'll be honest regarding my look-a-like Aeronova handlebar I didn't-which is why it was stationary-trainer-use only for a full off-season until I was confident it wouldn't net me a huge dental bill.