The costumes are completely different to the Egyptian styles.  Much softer and more feminine with scalloped edges and gradiated sequins.   Often a more delicate feel to them and the designers tend to love lots of fringing.

Bella is the top designer - a must to see if you want something really special.  There is also Madam Nihal, not as well known but her work is beautiful.  These tend to be fixed prices and are not as cheap as designs in Cairo.  If you are a professional dancer, it is good to have a full range of costumes and include a few from these designers as well.  Bella's showroom is easy to find - once you know where it is.  But when you try and find it for the first time .... it can take forever.

For cheaper options, the Grand Bazaar has many costume shops where you can pick up really cheap bra and belt sets and even designer rip offs of Bella's models.  Watch the quality - sometimes it can be very shoddy.  I take you to the main belly dance area in the Grand Bazaar and introduce you to many of the shop keepers.  Remember to barter.