There are lots of shops and stalls in Duval Street.
Some of them are certainly well worth looking at and exploring while there are others that are just trying to hustle you. For example the jerk with the McCaw who lurks in Duval Street and approaches you with the parrot. Once upon you he insists $10 to have your photo taken with the bird - using your own camera. Not nice to be hustled.
Otherwise Duval Street is pretty cool and well worth a look.
Just beware and tell the dude with the parrot to get lost!