Buying Electronics in Istanbul

I'm in need of a new mobile.  Are prices good in Turkey?  Where should I go to buy it?

Thanks! :)

I just came from US... Compared to prices  in US, it s a bit more pricey here...but if you have to buy electronics here, I would recommend Dogubank Ishani in Sirkeci area...Down the Sultanahmet... I hope that would be helpful...