I'm not happy with the trade prices given in the Mongoose rulebook, so I've come up with my own. The following costs assume a single Jump is being made.
Freight can be Standard, Fast or Slow. They define when a cargo is expected to be delivered by, and what sort of penalties are in place should delivery be failed.
If delivery is not made within double the allocated time, then the cargo is considered undelivered, and the ship is liable for the full cost of the cargo (as well as not getting any fee).
Encrypted and signed delivery notes are used to define acceptance and delivery times. Receipt is normally considered to have been made on loading of the cargo, and delivery on landing at the designated starport.