Shopkeepers are not pushy sales people but more relaxed and laid back unlike the ones in Marmaris and some touristic markets, Sarigerme is Hussle Free
There is no obligation to purchase a product when you enter a shop and been offered a drink, it is in Turkish Tradition to Serve and Host the Customer in the most pleasant way.
You can haggle if you believe that the item is not worth the price you have been given. But, ones you agree to a price it is very rude not to purchase.
In the shops of Sarigerme you can find all kinds of Shoes, Clothes, Sunglasses, Boots, Caps, Jeans, in the lowest price, but really good quality stuff for men, kids and women.
If you can not find what you are looking for in the sarigerme (unlikely) there are nearby towns such as Dalaman and Ortaca with more shops you might find it worth visiting if you are after big shopping.