I have bought a few things from Bluefly's Estate sale and was happy. It came in pristine condition but was in a generic box. Given the savings offered, I was happy with the transaction.
Estate jewelry can be used to refer to any pre-owned jewelry--so it can be relatively new. I ordered from the Bluefly estate sale before and was happy with the piece I got. I ended up not keeping it only because my husband had bought me something else.