Why do you have to buy anything? I like to make my Partner his favorite dinner - keeping it special and romantic; great wine, candles, flowers, soft jazz and a fire in the fireplace... Works every time!
How about taking him to a movie that he has been wanting to see and dessert after (I love Serendipity - wonderfully romantic and you can share a frozen hot chocolate) Or... Ice skating at Rockefeller Center A new exhibit at The Met or MOMA 50% off Valentine Tours for Two at MoMA
"This Valentine's Day, take a romantic and exclusive after-hours Tour for Two of MoMA's galleries!"
There are lots of things you can do in NY - together!