The problem here is that in the majority of cases taking the "loss" would be appropriate. However as soon as that is opened up you can guarantee the "stats" players will find a way to use it to increase the power of whatever realm is their favorite at that time. In some ways similar to how some players place characters in peaceful/rich realms for no other reason then to accumulate gold for the family to send off to their "active" characters. Sucks that we have to take precautions like this to try and limit the minority of players from playing against the spirit of the game, but that's a fact of game development.
1. Get rid of family wealth/asking for money
2. The minority who exploit weighs more than the majority who don't? (Don't quote Captain Kirk to Spock!)
You might as well get rid of movement towards regions because some other family members might just fake it and not actually travel. Get rid of messaging because someone may tell a lie to another player.
Taking a loss on trading can be a powerful political tool, or even just good hearted realm love. Don't tell me that as Banker of the realm I can't spend my own coin to feed my own country because some schmuck may game the system.
