If you are staying anywhere near The Fashion Show, and want to buy your own bottle of booze (or wine), check out ABC (located in the mall, so subject to mall hours).
The selection is limited, but for what you'll pay for a double-shot on the rocks of Stolichnaya at the DJT (lobby bar at the Trump International Hotel) you can buy the whole bottle at ABC.
Also a good place for snacks and mixers, or gifts for those back home.
If you plan to spend a lot here, even on more than one trip, save your receipts as you'll get a free gift when you cross the $100 mark.