I agree that if your task for the day it to go shopping, this is place to be... Much nicer than Istanbul's Covered Bazaar, less crowded (you can see sun & sky) and you can buy absolutely everything.
I was so angry at myself, that I didn't have too much space in my luggage, but still managed to shop a little bit. The best way is just to 'get lost' and try to find few hours later. You can buy there everything: carpets, fruits, precious stones (great prices!), live animals, spices, pickles, charcoal, local wines, clothes (!!!), leather gadgets & jackets, kitchenware, books - name it and you'll find it here. Prices are really good and sellers are actually nicer than in Istanbul.
If you fancy a Turkish coffee, there are local places to do so. Of course accompanied by some amazing local sweets, baklavas, halvahs or other stuff I don't remember name.
I would actually go to Izmir only for shopping. This is the best place in Turkey to do to.
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