When I have an impulse to buy something I don’t need, and later won’t care about, this is the method I use. I call it my “STOP” method.
S---Say, “No, not right now.”
T---Take time to think.
O---Overcome the urge.
P---Pat yourself on the back for being strong. Put the item on a wish list, and if it’s something you really want, give yourself time to reconsider. Then, if you decide it’s not worthy of your money, pat yourself on the back again.