Serious? Who uses 500 items on one charecter. No need to keep any craftable items or exotic weapons you can reacquire. Only keep the couple of exotic armor you use and delete. Any non featured gear is getting soft sunsetted so save couple of memory ones i guess but wipe that old stuff because it's useless in due time. D2 is basically turning to d3 without a full wipe. Not a bad thing. Also part of the game like others is inventory management not collecting. Choosing wisely is part of the game

If you have that many Tier 5's already, then they are easy to get. Get rid of the ones you most likely won't use. I have lots of Tier 5's also, and I play all 3 characters. But I still have room because I get rid of the stuff I will probably never use.