When visiting Turkey, and other places, keep in mind that haggling is not confined to the markets and bazars. Whether you enter one of the many outlet stores (which you should, it's dirt cheap), or if you're in an upmarket store in a posh mall you should never take the price printed on the label as anything than a rough suggestion. I've never bought anything at "list" in Turkey, and I've been going for more than 30 times and have purchased everything from a pair of briefs over a designer label suit to a washing machine to a car!
Only difference is you don't counter-offer with 20-30% of what a bazar vendor asks for when you're in a real shop, but 20-30% below list is absolutely a fair offer. If the shop attendant can't help you, ask for the manager. Helps a lot if you speak Turkish, or have someone with you who does, it must be added.