[Gzian]

As an alternative to my suggestions that ship offerings be improved based on the number of turns taken, you might not want to offer new ships at all. Instead, you might want to offer specials that can be added to our current ships such as increase fuel efficiency, increased benefits from weapons, increased defense, doubling of amount of items in care with same number of spaces, etc.. This way, we don't need to buy new ships that we have upgraded, and the specials come up in different spots from time to time in different cities.