You 100% can go with the cheapest HDMI cable you can find. Optical cables cannot be "jittery." They work...or they don't. Plain and simple. His job is to sell you stuff, and what he sold you today was a load off crap. I don't know how people can live with themselves doing that to customers, but I guess it is those same people that charge $50 to install a application that requires the user to simply click next 3 times.