It definitely is. The biggest problem is that so few colleges and uni's have Turkish on the curriculum.
I learnt a lot more from one thirteen week course at Dundee Uni than from any books or CD's. A lot of that may have been down to the teacher, but you can't beat having someone there, face to face, to answer questions and help with pronunciation.
The core textbook we used was "Colloquial Turkish" by Aarssen & Backus ISBN 0415157463 which you can buy with an accompanying set of CD's or Tapes. Even on its own its a pretty good starting point.
JF