Duty Free Shopping Spree is a pale lilac creme. Despite not sounding unique, none of the other colors in my collection along these lines are dupes (OPI Done Out in Deco, Essie Lilacism). The formula is fantastic; covered evenly in just two coats.
Ulta Pro polishes are on the expensive side. They retail for $7.50, but they are often on sale (currently they are buy one get one free).