There seem to be several major issues with the idea of selling a whole ship with items:
1. You already get a ship free at each rank WITH items.
2. Buying an additional ship is one of the bigger credit sinks in the game. If you were putting that money back into another players hands instead of it exiting the economy then that would have far ranging effects on the economic model.
3. Each item associated with the ship can have a different level and each would have to be checked against the level of the buyer before the ship could be put into your list of ships. Sounds messy and prone to errors and exploits.