Dead market is when you buy an item which the owner has not intended to sell. In this market, prices are often high because you[buyer] need to persuade the owner to sell that item...

Unclaimed means an item isn't claimed by the original owner or caretaker of an item. Any item that isn't shown ownership would be classified as unclaimed.

It is a sentimental item to you.

You go to the page of the owner of the item that you want to buy. You write how much you are willing to pay for that item. There may be other people bidding for the same item so you will have to bid higher for them but don't bid more than the item is worth.

It gets returned to its original owner if you lost it by death, or dropped/destroyed it.