I've tried to skim through most of these but if this has already been said, my apologies. The type of scent you are looking to wear plays a huge part in how long it will last as well.
Here is a scent pyramid:
Most of what you wear will be made up of parts form this chart. If you choose a bergamot/rose scent then you would expect it to not have the staying power of a scent that has primary notes of cedar and clove. Even if the citrus/floral is an EdP and the wood/spice is an EdT this could possibly hold true.
While yes, some of the niche houses and bigger names will tend to have more staying power because of the use of better ingredients, you don't have to spend a ton to find something you like. Sample some stuff in your price range until you find something that you like. The LAST thing you want to do is buy a frag outside your price range because of its longevity only to decide you don't like it after 6 months... Trust me... I've done it.