I think a Trade System would be a great idea for anyone, not just for Unlimited players, but
everyone.
My idea for it would beusing Lookout Games and there being an option for "Player Trade", or something similar. Then once clicked, there are players there that can click on each other and see each other's items in their inventory. Below the item there could be something like "Buy Item from $PLAYER$". Once clicked, $PLAYER$ gets a notification saying "$YOU$ would like to buy the item $ITEM$ from you." Then there is an "Accept" or "Deny" button.
This is just my idea for the Trade System.
Yes it would probably take them awhile to get this put in, but either way, it should be available to anyone.