Should you buy something (or not)? There is, sitting in the store window, all 36x24x4 inches of it – the plasma TV of your dreams. For the past two weeks it's taken enough willpower to bend spoons to keep yourself from slapping down the plastic and walking off with the thing strapped to your back. You envision it hanging in your living room like fine art, only better: this piece of fine art linked with the TiVo you plan to buy next will get 473 sports events per week including 24-hour high-stakes poker, all in high-definition surround sound. At least that would be the case if it weren't for the current featherweight state of your wallet. This equation weighs the desirability of the purchase against its practicality. If it's a good buy and you have the money, of course you should buy the item. However, if your desire and need fails to outweigh the cost and it's also a bit of an impulse buy, perhaps you should consider waiting for your heart to stop its consumer-frenzy palpitations. Or maybe think about investing this money in a safe place until your judgement improves.