A friend of mine once said:
"You might want it, but do you really need it?"
Yes, she said it when I was 14 years old and I wanted a pair of fluorescent neon pink platform heels which were actually awful! BUT that quote has stayed with me ever since she said it. I am still a shopaholic, everyone that knows me would agree, but sometimes I think of this and realise not to take it to far :)