I personally think it makes sense to have a good reason or purpose for any big purchase, dolls included. But I don't think whether that is: "wow! so pretty, I want it, no I NEED it!", or a detailed plan of the character you want to make, matters very much. Just buying one without either kind of motivation seems a little senseless to me though. In the case of sheer infatuation, I always wait on purchases and make sure that initial love doesn't wear off. When its worth the wait, you know you really want it!