Quoting erdinc:

University publications are sold to public. They are definately available to anyone on their campus bookshop. Sometimes they are also available on high street bookshops. Some universities, for instance Boğaziçi, have their online bookshop. Recently I called Boğaziçi University's bookshop for the book "Kayıp Çanta" as it was out of print.
They have a series of books for foreigners. For instance their famous " Turkish For Foreigners" books (2 volumes) are widely available on everywhere.
Here is a link to their official page:
http://www.bupress.com/ToolBoxVA/Tools/Mds/Scripts/Books/Series.asp?ID=174

Not all university publications are so organised. A few times I went to some universities just to buy their books. I remember going to Hacettepe and Ege Universities and the prices were comical. The bonus was that I could meet the author as well and talk about their books.
I met Ioanna KUÇURADI at Hacettepe university. She is a famous Turkish Philosopher and she was very kind as I didn't have even an appointment.

Quoting caliptrix:

I agree. In my faculty, some books are 5 YTL =~ USD 3.
Most of them are not more expensive than USD 10.

Quoting caliptrix:

It depends on the university and department

Quoting erdinc:

I think you will find the books very cheap comparing to the prices you pay now in your country. Only some imported books are going to be expensive but there aren't going to be any imported books related to Turkish Language and Literature.

Quoting caliptrix:

In my department, a price of an original copy of a book based USA is approx. USD 25-30. I need to have 3 or 4 books like that each semester (half year), but usually I don't buy the original one, even it seems cheaper than in Holland, it is very big amount for every student in Turkey, I think. So we get the photo-copies mostly. Generally, instructors allow that.

I just saw that restriction when I was in English preparatory class. I think, because some investigators from Oxford Pub. used to come and look sometimes.

Quoting erdinc:

Many universities in Turkia have their own publications and they have a bookshop inside the campus.