The world's priciest foods

Saffron, the most expensive spice, is usually sold by the gram - just a small cluster of slender red threads in a tiny glass bottle. At the Spice House in Chicago, owners Tom and Patty Erd sell a gram of superior grade saffron for $6.79, and an even finer version, known as coupé grade, for $8.29.

The threads are the stigmas of tiny crocuses, grown primarily in Spain, Iran, Greece and India. Since each flower only has three stigmas, many blossoms are needed to produce even a small amount of spice. It takes an acre of land and hundreds of thousands of flowers to produce one pound of saffron threads.

Saffron, which Patty Erd calls "a classic," has been a key ingredient in cuisines since ancient times, and it is commonly used to make risotto, bouillabaisse and paella. Fortunately, a little saffron goes a long way and most recipes call for just a pinch.

"There are 200 to 300 threads per gram, and you only need a few threads at a time," Erd says. "You use it so sparingly that in the long run it's not much more expensive than any other spice."

But be careful to invest in quality, advises Vanilla Saffron Imports president Juan San Mames. His San Francisco direct-import business currently offers saffron for $1,162.24 per pound, or $72.95 per ounce, and carefully vets its saffron for compliance with ISO standards. (Yes, the ISO has saffron specifications.) Cheap saffron producers often leave in the tasteless yellow stamens, adding weight and diluting the red stigmas that give the spice its famous taste.

NEXT: Kobe beef