Several years ago I took the late LH flight from Munich to Ismir. THe Havas bus stops running relatively early and I have heard stories form natives that taxi at night is risky, due to the prices they charge: night surcharge, arpt surcharge, bad meters, etc....
I contacted my hotel, Crowne Plaza, and they provided a transfer for an equivalent (normal) taxi fare.
Good thing as our flight was about 1.5 hrs late and the driver was there waitning on me !
I finally took the train to Alsancak for 6TL and from there a taxi to the Hilton for around 12TL. This way is pretty easy and comfortabel. The train station is signed everywhere at the airport and the trains run fast and frequently. Very modern and comfortabel trains btw.
On my way back I was a little bit in hurry so I took a taxi right from the Hotel and paid 45TL which seems to be the normal fare as the concierge told me exactly that price.