I'd be a little suspicious of el cheapo cable with copper plated steel
center conductor. I'd be surprised if it was Copperweld, which has a
very thick copper coating. Copper plating thickness would be a logical
place for cost-conscious vendors to skimp.

An extra thin layer of copper wouldn't hurt at VHF and above, but it
could really be a killer at HF, where significant current could flow in
the steel. (Steel is extra lossy at RF because its permeability further
reduces the skin depth by a large factor.) I'd definitely measure the
loss if I intended to use it at HF.

Of course, many (or most) amateurs would probably be pleased by the wide
bandwidth and low SWR and noise level they'd get with lossy cable.

Roy Lewallen, W7EL