Unless your HDMI devices actually support Ethernet transfer via HDMI then it doesn't really matter. Support for Ethernet over HDMI didn't come along until version 1.4 of the HDMI spec.
I have several $2-3 HDMI cables in use here and they work just fine. IIRC, I got 3 for $6, including shipping from Meritline. I also have a few from Monoprice that were very cheap, but only because I was already buying other, heavy items that covered most of the shipping charge.
There's enough HDMI spec info here: »en.wikipedia.org/wiki/Hdmi
to give you a headache.