One of my favorite inexpensive guilty pleasures are (is?)the 35 cent truffles sold in bulk at the Lindt store on 5th Ave near 56th Street. Each truffle is individually wrapped. They come in milk, dark, peanut butter, orange, mint and a few more that I am blanking on. Peanut butter ones are the best.
Today I decided to try the 50 cent bulk truffle "eggs" instead -- I thought they would be a slightly bigger truffle and more bang for the buck. But I was disappointed in them -- the much thicker chocolate shell detracted from the overall experience.
The box of mixed tiny chocolate bars (found in most European duty free shops) is also a great tasty deal.