Paul.
Just departed 20 days ago. You can find any of these items in the airport. There are three areas to purchase items at the airport.
1. Outside before going to the ticket counter
2. Inside bottom floor Duty Free area just past immigration is a large area with many vendors selling all kinds of alcohol, perfume, and Dominican goods.
3. On the second floor Duty Free area in the center of the waiting area where the airline departure gates are.
Prices will vary from place to place, I thought the best prices were at the bottom floor Duty Free area were best, but I did not buy anything, just looked. You really need to look carefully at the volume of items. I looked at one type of alcohol and thought it was cheeper somewhere else then noticed that there there 4 different sizes of the same product, each with a different price of course. So when you compare be sure the size is the same.
I don't think the Duty Free shops will bargin.
bonnie green