First of all I would prefer to buy mobile through e-commerce rather than shops.But if you don’t want to buy through online and want to inspect mobile physically then you can head up to mobile shop but you got to keep few things in mind.First just evaluate what features you want in a mobile i.e camera quality, sound perception, display quality, look etc.
Try to get a buddy with you to the shop who has good knowledge about mobile.Choose a genuine and good reputed shop.Tell the sale agent about the budget and the features you want.Don’t believe all the thing whatever he says , try to inspect things by your own self.Remember they will nokia 2610 by claiming it as iPhone 6, because that is the job what they are doing there.Just open your net and try to get maximum knowledge about the phone.If they are praising too much just leave that shop.