I bought one Yamato by mistake and it ended up on wrong planet, I clicked and expected a confirmation window on purchase, and on which planet I want to deploy the ship once I purchased it.
It should go something like this: Are you sure you want to buy this item? Yes or No. If yes send this item on planet of your chosing. Not on planet you happen to be on while buying the item. Mistakes will happen like it happened to me :)
This is something you need to implement.