Dubai bargains depend very much on what you are looking to buy... Fashion is same price if not more for the standard high street brands, Debenhams / M&S / Next, designer isn't significantly cheaper.
Jewellery is good value but only if you know what you are going for, the standard gold is the yellowish gold (is it 22 carat?), which may or may not be your thing... personally I dont' like it.
Dubai is currently being compared to a buildig site as there is a huge amount of development going on, at the moment I would personally avoid going there.
Recent recommendation from friends is Hong Kong for some good value fashion, when you hit the markets.