Interesting idea.

http://lifehacker.com/5320196/use-the-s ... -purchases

When considering a purchase, picture a stranger offering you [the cash value of the purchase] or the item in question. Which is of greater value you? Which would you choose?

If a stranger were to come up and offer you $3 to not buy that cup of coffee you might reply "Thanks, but I'd really like this cup of coffee." But if your response over a bigger purchase like a new HDTV set or a computer would be "Hmmm $800 would be a pretty nice credit card payment..." it's probably best to put your funds to use fixing more immediate problems.

How about "Hmm, $800 would let me buy that smaller TV and have some money leftover for popcorn" or "Hmm, if I keep that $800 this month and save up for a couple of more months I can buy that better TV.

Well, impulse buying is what the words imply. It is an impulse. It would not be an impulse purchase if you actually think about it. You're standing in line at the supermarket and you see a candy bar and immediately grab it because it is cheap and is convenient. You did not have time to do the "stranger test". I don't think this applies. That IMO.