With the amount of duping still going on, re-enabling the Marketplace would be a big concern as many items would be duped and those "first come, first serve" items would be prime pickings for duping to make massive profit. However, with this in mind, there could be some safeguards in place to nullify or drastically reduce the amount of duping of these items, such as the Two Chupacabras Perfume, Inventory Expansions and much more.
Making all items purchased on the Marketplace untradeable or only tradeable within your own account would reduce the risk or entirely removing the chances of these items being duped. Many times I see players wanting the Marketplace re-enabled to bring some QoL items back into the game, such as Inventory Expansions, Faction resets, cosmetics and much more. I, for one, never managed to purchase anything before the shut down but would love to be able to support the game and the studio to be able to give back and help support the development of the remaster or to get some much needed updates for Classic.
Therefore, I recommend having all Marketplace items be tradeable within your own account (mail to other toons within your account) or flat out untradeable with the item being purchased locked to that toon. This would enable players to purchase items they want without the chance of them being duped as they aren't tradeable and can't flood the auction house.
