While prices drop sales for flat-screen TVs are booming. You might have received one for Christmas, but the hidden cost of your new flat screen: electricity. A lot of people don't about out how much juice their flat screen is sucking in. Depending on what kind of flat screen it is, it may be a lot. "I try to be sort of concerned about that sort of thing, power consumption and such. So yes, I think that would make a difference in my decision," shopper Alex Pappas said. At R.C. Willey, like most electronics stores, regular cathode ray-tube TVs are almost extinct. Flat screens--LCDs, plasma screen, and projection TVs--seem to be on everyone's wish list. "They've continually had about a 20- to 30-percent increase each quarter. So, they've been very good, and a lot of that has been because of the going away of the picture-tube televisions," explained Claire Mitchell, of R.C. Willey. According to separate research from England's Oxford University, the ...