Luxury Foods include foie gras, caviar and truffles

What exactly is a luxury food?

I set out to try and find a list online of what other people thought of as luxury foods and by combining lists from other sites these are what I came up with:

Caviar, Foie Gras, White Truffles, Kobe Beef, Liqueur chocolates, Saffron, Bird's Nest, Fugu fish, Lobster, Matsutake mushrooms, Oysters, Abalone, Ambergris, Musk, Sea bass, Wild Salmon, Vanilla beans, Balsamic Vinegar

An interesting and eclectic mix with Fois Gras, Black Truffles and Balsamic Vinegar available from us online.

Some of these items are clearly considered luxury because of their rarity or cost but others like Salmon, Oysters and Lobster were traditionally viewed as cheap everyday foods near where they were produced. 

I have never eaten about half of them and I'm not sure that musk, fugu or ambergris are high on my must try list.

What would be in your luxury food list?