I'm flying to Istanbul tomorrow afternoon and would like to know the cheapest way to get from the airport (Ataturk) to the Taksim Square area. I'm sure there are many options and some will be easier or more comfortable but I am on a shoestring budget and sometimes like to do things the hard way as the less wealthy locals might have to.
Municpal bus 96T is probably the cheapest, at 3.00 lira (~$2 USD), but it takes very long (~1.5h at times) and is often packed. Havas bus is faster and costs 10 lira (~$6.50 USD).
If you plan to use public transport a lot, buy the Akbil pass (saves a bit of money and you don't need to dig for coins all the time).
The trip is also possible via metro, but involves changing over twice (Zeytinburnu to tram and a short walk at Karakoy to Tunel). This takes 3 tokens (jetons), and costs 3 x 3 = 9 lira (~5 USD), in 2012.
Using the Istanbulkart (Istanbul's Oyster Card) you can make it to Taksim with 4.75 TL.
Buying 3 Jetons would make 12 TL instead. Using the Istanbulkart is only useful if you use public transportation more than that one time since it costs 6 TL to get the card in the first place.
There are three public transport options if you are trying to minimise costs.
The tram line between Zeytinburnu and Kabataş is the worst option, especially if you change lines at Zeytinburnu. It travels very slowly (especially between Zeytinburnu and Aksaray) and it does not travel to Taksim, so you will have to walk uphill or pay for a third fare. The best bet with the tram is to change lines at Aksaray, but this involves the same 5 minute walk as going to the bus stop
If you do take the tram, you can get off at the last stop (Kabataş) and, as mentioned, take the funicular up to Taksim at the north end of İstiklâl street. You can also get off the tram earlier at Karaköy, where there is the two-stop Tünel (Istanbul's 100-year-old metro line) that takes you to the south end of İstiklâl, from where it is a pleasant 20-minute walk to Taksim square. Walking from Karaköy up to İstiklâl is also possible and the road goes right past the Galata Tower.