Hey Shaggy, Frieda's Finest is one online vendor with some interesting and exotic offerings. It even appears there must be a glut of mangosteen and they are running a sale and run
only about $3 per fruit!
Frieda's Inc. - The Specialty Produce Company I've bought the imported ones a couple of times in the Bay Area markets and they were very good. A friend who had bought some at these same markets bought some from Frieda last year and he said they were the best he had had.