Shops are decent at SJU, but if you have enough time...take a quick cab ride over to Isla Verde and catch some rays on the beach. It's literally no more than 10 minutes, "door to door."

You may want to pose this question in the AA room since their SJU presence is much more significant than that of UA. (Or now, as I understand it, "Ted." )

And on second thought, you'll probably want to twist your question so it relates to either UA or AA as I get the sense this thread will make its way into the SJU forum where nobody ever visits.