An interesting scam to be aware that might relate to a game bug.
I had an odd experience buying from one of the Perimeter Citadels in the last week. After buying an item I set my destination to the Citadel via the Market Entry. When I docked I found the item was not there. Checking my personal asset list it showed it was in a Citadel with the same name, but a location as system instead of station. I used the personal asset list to set a new destination, undocked, and flew to the correct Citadel to pick up my goods.