why do people spend so much on low level items with high ee when they know in only 5-10 levels they're going to need to sell that and buy a new expensive item, why don't they just buy something with 20 ee lower than the recommended in the guides at that level

because people like to have a great item in his property and also make a huge damage in solo and cata too

If you are playing correctly and investing the fg necessary to even bother buying high EE items. You keep those items you don't re-sell them later.

and you keep doing the same thing each time you upgrade till you have a full set of high EE weapons. Armor Or Charms..Whichever may be the case.

i keep all my gear
for each level
one day
i dont have to buy anything for anyone