The Three Twins Ice Cream shop in the Oxbow Public Market in Napa is selling the World's Most Expensive Ice Cream Sundae for $3,333.33 (a banana split made with syrups from three rare dessert wines, served with an ice cream spoon from the 1850s. If you order a day ahead, they'll have a cellist perform while you eat).
But if the World's Most Expensive Ice Cream Sundae is not glam enough, you should try their "The World's More Expensive Most Expensive Ice Cream Sundae". For $60,000, you'll get ice cream made from the disappearing glacier from Mount Kilimanjaro in Tanzania, Africa!