A Turkish visa is only $45. and if it was just a port of call they do everything for you on the ship. I think since you're flying in you have to arrange it in advance.
I use a service online for such things. the address is www.samspassport.com or 1-877-784-5501
Sorry for the slow reply, I just noticed the question while searching for something else.
Thanks Neil. This service will not work for me because I am a canadian citizen but may benefit other readers. I think it will be wise for me to obtain my visa prior to leaving Canada from the Turkish Embassy in Ottawa. This way I will not have to line up at the airport in Istanbul and avoid any pssible complications. Thanks again. John