And the side effects with the system i suggested are..?(Not saying there aren't any just i believe the dimension of trading being added to the game outweighs the possible cheating loophole..which i still believe is very slim given the restrictions I've suggested)
You need too players with the same value(or packages), wo both GM desire the one from opposing team i think at least that it rare - which lead to mostly unfair trades for one side or just waist of time looking through the avaible players.