"EAR VS Cables"

guys,
first of all.i want to thanks all the fellows audiogon on here helping me finish my system..i am pretty much completed everything but cables.after 3 months reasearching about cables on here,and i am still confuse of which cable to buy..i ve tried(borrow) home depot cable Vs $1000 cable,to be honest,i can not tell the difference whatsoever.I am an electrical engineer for 11 years ,and to me there is no theory that support the differences on cables.anyways,is it because i am not at the level that my ear can tell the difference? Am i going to get there one day? the question is..should i spend the money now on cable or stick with the cheap affordable cable?my ears can tell the difference between tube and SS,but fail on cables..when i say cables.i mean inter-connct,power cord, and speakers wire. ..please help.