By Rusty Marks CHARLESTON, W.Va. - With Thursday-afternoon temperatures struggling to claw their way out of the mid-30s and a menacing sky threatening to spit snow, Debbie Amos sat huddled against the wall beneath a fuzzy brown blanket outside Charleston's Best Buy with her partner, Keith King, waiting for 5 p.m.That was when the electronics retailer was scheduled to open its doors for a pre-Black Friday sale."I'm pretty cold," conceded Amos, who nevertheless intended to keep her place in line for a shot at a 50-inch flat-screen TV, advertised for $199."It's for my kid," Amos said.