I planned a private dinner at the GF as a surprise for DH to celebrate our 15th anniversary last year. It was wonderful! We had our own butler and a romantic private nook on the 5th (I think!) floor. We would've been outside, but it stormed that night. But it worked out great, as we could hear the live music from the lobby. I worked with Linda in private dining at the GF. Our meal consisted of champagne, salad, crab cake appetizers, an entree of filet and lobster tail, and a custom cake for dessert. Including tax, butler fee, and gratuity, the meal came to $400. It was by far the most expensive meal DH & I have ever had, but it was worth every penny! I chose this option over V&A mainly because our tastes aren't quite as gourmet as dishes I've seen from there. We like variety, but hated to pay that much for a meal we might not like.
Have fun planning!