I love this question. A few ideas:

1) Artwork from an up and coming local artist: a print or drawing framed would be wonderful. 10-30k depending on size.

2) City Tour from the GM in some sort of wonderful vehicle. 10-15k.

3) Having a musician or set of musicians play in your sweet- you could invite friends and colleagues. 20-40k.

4) A cooking lesson from the chef in the kitchen: 10-15k.

5) Custom Tailoring.