One rule that has worked out well for me is "Cost per wear" or "Cost per use". So for a clothing example: if you wear the item a lot and it lasts a long time, then the "cost per wear" keeps going down over time, so even if it's kind of an expensive purchase at first, the "cost per wear" is what really should be considered. For a nice jacket, a nice pair of jeans, a nice pair of shoes etc., the "cost per wear" can actually be quite low, and that's a good thing. The worst scenario is if you buy a pricey item and you only wear/use it a few times, purchases like this should be avoided.