Borderlands how to get better loot and cash level 16

First. make it to Headstone mine then get the checkpoint.
then after that you will go around the area grabbing all of the crate content then once you got them all exit the game to menu and reload the game then repeat till you feel like you have what you need
you can find Class mods Grenade mods and lots of purple loot this way but it can take a few attemptes you can then sell whatever you do not want

Example