I think there is no answer, the question is too inaccurate.
e.g. half value of what?
Which set is meant?
How much gold does it send to other partners?
... only then you know this you can analyze this problem, usually send passenger trains (regardless of how much gold you own) gold to neighbors / contractors depending on to how many you send a train (max 8) ...
A point has been named in the comment before ! passenger shortage.
Wizzard Express example, need 5,9M Passenger for send 67M Gold to 1 (one) recipient
but need 6,8M passenger for send 38M Gold to 2 (two) recipient etc.
→ that means you send this train (or similar) 10x to Cornelius (single receiver) and the task is done ...