It would be quite cool if this would be added. Obviously they wouldn't add any stats, they would be there only for the appearance. For example: A certain player has BWG with 15 attack, and over them, he has the Stormcaster Gloves equipped as a cash item, that's untradable and adds no stats. It could be a donator feature, and people would have to give in 2 RPs to make a normal item a cash one(just an example).
http://royals.ms/forum/threads/allow-us-to-use-normal-items-as-nx-cover-up.19275/ This has been discussed before.
This was discussed twice: http://royals.ms/forum/threads/request-fusion-anvil.10374/ http://royals.ms/forum/threads/allow-us-to-use-normal-items-as-nx-cover-up.19275/ General consensus was that this won't be available anytime soon. Here was Matt's responce: