Welcome to LS!
For figuring out what is worth keeping, I suggest you keep this link handy:
http://forums.d2jsp.org/topic.php?t=32190773&f=272Also, items under 20fg shouldn't have threads made for them. They should be on MP. As a friendly reminder, upto 20x items can be placed on marketplace for 19.99 and lower and the fee will be taken out AFTER the item sells. So basically, they cost you nothing to list

Best of luck to ya!