Why then when I purchase a ship the starport says it will be completed in 0 turns but I need to wait 1 turn for it to complete?

Red tape - don't forget you'll need to get it M.O.T.'d and taxed before you can take it out.

Actually, it was just a quick post in which I was erroneously redundant with my wording, which one guy picked up on and then another made it into some sort of veiled insult that was quite beyond my humble capabilities. I just use big words to hide the fact!

In any case, I think that the gist of what I said came across without needing to disect and correct, eh? >.<