I have a feeling the karachi authorized dealer will try to charge you more than MSRP simply because he knows you dont have any other options.
The Dubai Mall (downtown near Burj Khalifa) has the best collection of watch dealers concentrated in one place. Rolex, Patek, AP, Richard Mille, ALS, Omega, VC, IWC, etc. - all within about 100 paces near the entrance to the aquarium. The Rolex boutique had 16 different Daytona's in the case the other day (including the two SS and a platona), Hulk, BLNR, Smurf, and several dozen DJ's of various sizes and configurations (I guess I'm saying it's a pretty well stocked boutique).
I've stayed at the Armani Hotel at Burj Khalifa and recommend it for business or leisure.