What is the AliExpress experience like in Dubai?

I've had a good experience with shopping online, but be aware that once you place an order, you can't cancel it, so you'll lose the customs charge. You can chargeback, but it'll take at least 3 months to resolve. As for finding a seller at Dragon Mart, you'll probably find what you're looking for, but it'll be overpriced, and you'll have to haggle to get the price you'd find online.

I've had no issues with shopping online, and I've returned an item once, which was credited back as store credit. I'm not sure what you're looking for, but you might want to try a store in Karama or Kabayel.