引用自 Pum：

www.tf2items.com is a very good site to check duped hats and history

Except when you view newer items, it only displays an error that the ID could not be found.

I don't know about any website that still keeps track of item history to this day. Even if they did it'd still be incomplete. As for how to know if an item is duped? You check similar hats and look if their original ID match. On Outpost if you click on one of your items and you are not listed as the last owner, the item is most probably duped.

Mods only close inactive trades when they keep getting bumped even though they're out of stock. Nothing wrong with bumping your trade when you get new keys, just make sure you also edit your notes to reflect that.

引用自 CA$EMOD$：

I always sell my stuff exactly what it's worth on backpack.tf at the time...even if it's the lower range of the prices (I'll pick 1.33 if it's worth 1.33-1.66)

The site is just a guide, you shouldn't follow it. Use your head.

Just stay away from people offering you "super quicksell" deals and you'll be fine. Always check their Steamrep page, make sure their account is at least 1-2 years old with tons of comments. If an account is private or is very new and has high value items simply do not trade with them. It's a dead giveaway. No matter how good the deal is, it's not worth it. You can be marked on Steamrep for trading with obvious scammers or even worse, have your account locked for being part of a possible hijacking.

Because if you cannot restock in less than a week, you might as well close the whole trade and reopen it when you have Keys again.

There should also be a seperate section for them called "Community" or something. More and more cards are released and they're only cluttering the gifts category.

You can see the nickname Sneeza™ in the list of his previous aliases which can count as impersonation. He did lie about the item too which can be called scamming.

I noticed that all expired trades have this message displayed, it's probably affected by this change:

- FEATURE: Added third trade status - expired - to make it easy to differentiate between trades closed by admins and those closed by admins.

I think there's a ban appeal page when you visit the site.