I have never understood layaway, is there some advantage to letting them hold your money? Maybe it's the same idea as paying too much in income tax to receive a bigger refund.
Why not take $20 a week and stuff it in an envelope, and then when you have enough money saved up you go buy the TV? That way if something in your life changes and you decide you don't really need a 55" TV as much as {food, rent, car insurance, Jeep parts, etc.}, you still have an envelope full of cash and there's no cancellation fee. Better yet, even if you don't want to buy anything, stuff $20/week in an envelope anyway and enjoy having $1000 a year later.