Also it depends on the port. Long ago, Miami used to have liquor store inside the pier building. I don't remember seeing that in most other ports. But, even if you find one, the cruise line will still confiscate it, so no cost savings there!
Congrats on the cruise! I hope you report back to let us know where you went and how you liked it.
There are some duty free stores at some ports. I have been known to purchase a few of the little bottles and have simply placed them in my back pack with no problems. As I stated earlier, it is not allowed, but many do it. I actually drink so little that it is not a big deal for me.
Have a great tiem, and think of us who have no cruise booked.