I don't know too many places here at home, where you can go into a jewelry store,and bargain for a better deal. Maybe in a Mom & Pop, place, there is a bit of wiggle room.
At home, in order to see the diverse inventory you find in a port like St. Thomas, you would have to drive all over creation, and still not see selections like you can, just walking into a few stores there.
Your deal in port, can also be determined by how many ships are in, & if you will pay cash, which, will always get you even lower price, since the shop is not paying the fees to the cc company.
I do not like to bargain, my hubby does it for me...but, the majority of cruisers in port enjoy it, and, like markets around the world, it's expected.