You're going to be told many things and given many offers this Black Friday, but we'd like to be the first to tell you not to get trapped by the following. Do not buy a cheap tablet on Black Friday. Do not fall for this trap. The math does not add up, no matter how you sling it. Show me the cheapest tablet at any given store on Black Friday and I'll show you why you shouldn't buy it - and why you shouldn't even consider it.